Corrosion Resistance of TiNi Alloys

TiNi alloys in natural atmospheres and waters are generally more corrosion resistant than 316stainless steel but not as resistant as pure titanium. A passive oxide/nitride surface film is thebasis of the corrosion resistance of these three material. Specific environments can cause thepassive film on TiNi to break down , opening the alloy to attack. The accumulatedexperience with TiNi will be presented as corrosion by atmospheres, by waters, by organicchemicals, by inorganic chemicals or by biological environments.

Corrosion by AtmospheresPolished TiNi remains shiny in air from ambient temperatures up to about 100C at whichtemperature the oxide/nitride surface layer slowly thickens giving the interference colors. Upto about 700C, a tight, thin, blue-black oxide/nitride film protects the TiNi. Above 700C,the layer thickens into a more porous brown and yellow scale. No absorption of oxygen intothe alloy or internal oxidation occurs (933), thus TiNi behaves more like stainless steel atelevated temperatures than like titanium alloys.

If TiNi at ambient temperature is impinged by pure oxygen gas at progressively higherpressures, flashes and sustained burning begin above 150 psi absolute. By 500 psia, 16 out of20 tests produced flashes and burning (2942).

When TiNi is heated to 700C in pure nitrogen at atmospheric pressure a beautiful gold-colored, somewhat brittle, surface layer forms.

The interaction between hydrogen and TiNi is sensitive to hydrogen concentration , pressure,and temperature. TiNi remains ductile after having been heated to 750C in hydrogen gas atatmospheric pressure , then returned to room temperature. However, TiNi exposed tohydrogen gas at 360C becomes brittle and crumbly (2956)(2930). If nascent hydrogen ischarged into TiNi, a brittle surface layer forms and thickens with time (373). This will bediscussed in more detail in the "waters" section. Also, if TiNi tensile samples are elongatedwhile surrounded by hydrogen gas at 7,000 psi, brittle failure occurs; immediately uponreducing the pressure to one atmosphere, the failure mode is again ductile.

The presence of gaseous hydrogen fluoride in damp air at ambient temperatures has causedsurface etching and stress corrosion cracking in bare TiNi couplings (3003). Condensationwas occurring on the couplings, however, so this should probably be considered as attack byhydrofluoric acid.

Corrosion by WatersTiNi is not attacked by fresh water. Even in pressurized boiling water (PBW) at 300C foreleven months, TiNi gained only 15% as much weight as Zircaloy-2 (3011). The same sortof PBW at 340C and 20 ml / kg H2 causes little damage. Water at 360C with 100 ml H2 /kg causes TiNi to crumble to dust; the diffraction pattern of the dust shows only the presenceof TiH2 and Ti2Ni (2938).

TiNi resists attack while immersed in flowing sea water. However, in stagnant sea water asin crevices, the protective film can break down resulting in pitting (2945). When TiNi isexposed to a marine environment which cycles from salt mist in the cool of the day toevaporation during the heat of the day, tunneling corrosion can occur (2953)(1130 ??).Small, residue-free pits form on the weather surface while branching tunnels penetrate intothe bulk of the metal (tunneling corrosion has been reported in austenitic stainless steel undersimilar conditions (2950)). This same type of corrosion occurs when the salinity exceedstwice that of sea water and the pH drops below two. Addition of sodium hypochlorite to seawater causes a similar phenomenon.

Salt spray tests are often used as an accelerated indication of longer term corrosion resistance.TiNi passes these tests (83). In one case Cryofit couplings joining titanium tubes weresubjected to a six-day cyclic test in 5%-salt-plus-sulphur-dioxide spray. All assembliespassed the test. A year later one of the unwashed assemblies was found to have cracked.Sectioning revealed that tunneling occurred through the coupling, starting from the insidewhere electrolyte had been trapped between the coupling and the tube (2944).

Special effects have resulted from electrical currents and saline solutions. A cycling plus-minus 5 volt applied to TiNi in a l50-ohm saline solution caused grain boundary crackingwithin 150 days (2948). Also, when TiNi was made the cathode in a cell with a salineelectrolyte and a voltage which caused hydrolysis of the water, the TiNi was charged withnascent hydrogen. For several days after removal from the cell, chips of TiNi would forciblypop off the surface, especially at corners (2949).

Corrosion by Organic ChemicalsAcetic acid, CH3C00H, attacks TiNi at a modest rate of one to three mils per year (mpy) overthe temperature range from 30C to the boiling point and the concentration range 50% to99.5% (2232)(589). The attack is fastest at the lowest concentration at the highesttemperature and at the highest concentration at the lower temperature. Seventy per centacetic acid with 0.1% formic acid, HCOOH, attacks at the same rate as 70% acetic acid: 0.3mpy.

A study reported 5 mpy attack rate in O.5M oxalic acid, H2C2O4, at 50C (1063).

Methanol, CH3OH, has a mixed history. A steel pipeline on the bottom of the North Sea wasused to deliver methanol as an anti-freeze to gas wells. An undersea repair was made to theline using a TiNi coupling which served without problems for several years. A similarinstallation on a new drilling platform off Scotland leaked within hours after being filled withmethanol (2952). This occurred again with several methanol line couplings under Lake Erie(2957). Tunneling of a type similar to that found with special marine exposure situations wasthe cause. Low concentrations of water and halides in methanol cause attack on titaniumalloys whereas pure methanol or more contaminated methanol does not (2951). Perhaps thisis true for TiNi, too.

A 15% solution of iodine in polyvinyl pyridine at 37C and at 60C caused severe cracking ofTiNi couplings within one month (2946).

TiNi was not attacked after three months in a urea, CO(NH2)2, solution at 110C (589).

The hydraulic fluids, Skydrol 500 and Aerosafe 2300, at 125C and 135C, respectively, for20 hours caused no attack on TiNi couplings. This preliminary observation has beencorroborated by many years of satisfactory TiNi service aboard aircraft.

Corrosion by Inorganic Chemicals

TiNi has been exposed to a number of different inorganic chemicals singly or incombinations and mostly as aqueous solutions. The observations will be presented inalphabetical order:

Liquid aluminium can attack solid TiNi (2941).

Aluminum nitrate at 6.2M concentration and 50C attacked TiNi at a fraction of a mil peryear. However, 0.3M Al(NO3)3 + 0.6 M HF + 12 M HNO3 attacked at 1300 mpy(1063).

At 50C, 6.2M ammonium thiocyanate, NH4SCN did not attack TiNi(1063).

Boron trifluoride plus hydrogen fluoride dissolved in water condensate on Cryofit couplingsattacked at 20 to 40 mpy in a pitting mode and led to stress corrosion cracking(3003).

Bromine dissolved in methanol can chemically polish TiNi.

TiNi has been exposed to liquid cadmium with no ill effects(3005).

Calcium hypochlorite at 70C attacked at 15 mpy(2232).

Chromic acid at 10% concentration and 70C attacked at l mpy; 50%, at 2 mpy. One per centchromic acid plus five per cent hydrochloric acid attacked at 18.5 mpy. Chromic acid at6.8% plus l.5% ferric chloride plus 9% hydrochloric acid attacked at 2,200 mpy. Half a percent chromic acid plus 5% sulfuric acid attacked at 1 mpy(2232).

Copper chloride at 70C attacked at 215 mpy(2232).

Ferric chloride at 8% concentration and 70C attacked at 350 mpy. One and one half per centferric chloride + 2.5% HCl attacked at 110 mpy; + 5% HCl, at 120 mpy; + l0% HCl,dissolved the TiNi(2232)!

The attack of hydrochloric acid on TiNi has a strong dependance on temperature, acidconcentration, and the specific alloy composition. With 3% HCl at 100C and a range ofalloy compositions, the rate of attack was as low as 14 mpy and as high as 129; with 5% HClthe rate was from 14 to l,667 mpy. At room temperature with 7 M HCl, TiNi "A" lost from9,000 to 18,000 mpy(3004)(2232)(1063)(2233)(589). Preliminary results indicate thatgaseous HCl can cause stressed Cryofit couplings to fail within minutes(3010). Curiously,equal parts of concentrated hydrochloric acid, concentrated nitric acid, and water at roomtemperature remove the heavy scale from hot worked TiNi without noticeable attack of thealloy.

Hydrofluoric acid: no data available.

Combinations of hydrofluoric acid, nitric acid, and water give some of the most usefulsolutions for chemical surface treatment of TiNi. Descaling, metallographic etching, andchemical polishing at various rates can be achieved by adjusting the ratios(1063)(3009). Onepart of 40% HF, one part concentrated HNO3, and two and a half parts of concentrated

H2SO4 also brightens TiNi(3010).

Hydrazine did not attack TiNi "A" in a 49-day test at 85F. A 16-week test at 70F alsocaused no attack.(3000)(3001)(2939).

Nitric acid is more aggressive toward TiNi than toward austenitic stainless steel. At 30C,10% HNO3 attacked TiNi at 1 mpy; 60%, at 10 mpy; 5% HNO3 at its boiling point attackedat 80 mpy. In another test at 50C, 3 M HNO3 attacked at 11.5 mpy, 7.5 M at 29 mpy; and12 M, at 30.5 mpy. Red fuming nitric acid at room temperature caused extensive weight lossand pitting of TiNi within 48 hours(3008)(587)(1063)(2232).

The combination of 7.5M nitric acid with 0.02M sulfuric acid caused just 9 mpy attack on aTiNi coupon. However, a TiNi coupling on a 304 stainless steel tube lost 29 mpy whereasthe stainless steel lost none(1063).

Nitrogen tetroxide, N2O4, caused no attack of TiNi during a 49-day exposure at 85C.

Mercury did not attack TiNi(2941).

Attack by phosphoric acid is a strong function of concentration and temperature. At 30C, 5%H3PO4 attacks TiNi at 0.5 mpy; for 50% H3PO4 at the boiling point the rate is 2,300 mpy.A Cryofit coupling immersed in 105 weight per cent H3PO4 at 400F "completely dissolved

within 48 hours"(3007)(589)(2232).

bxl24One

bxl24part of 40% HF, one part concentrated HNO3, and two and a half parts of concentratedH2SO4 also brightens TiNi(3010).

bxl24hydrofluoric acid,

bxl24nitric acid,

bxl24water

Potassium hydroxide does not seem to attack TiNi. Seven hundred twenty hours exposure to6M KOH at 50C caused no loss of TiNi(1063).

A Cryofit coupling joining two 304 stainless steel tubes was pressurized with helium. Theassembly was immersed in liquid sodium at 482C for 30 minutes, then returned to roomtemperature. On the sixth cycle the assembly leaked. The failure was attributed to creep;attack of the TiNi was not reported(3002).

Sodium hydroxide at 20% concentration and 30C attacks TiNi at 0.4 mpy; at the boilingpoint, 1.6 mpy(389)(2232).

Binary TiNi is attacked by 5 wt. % sulfuric acid at l00C at 8,200 mpy; by 10 wt. %, at14,300 mpy. For highly alloyed TiNi, l% sulfuric acid at 30C attacks at 0.4 mpy;concentrated sulfuric, at 84 mpy. At its boiling point, 0.1 % sulfuric acid attacks highlyalloyed TiNi at 0.3 mpy; 5% sulfuric acid, at 460 mpy. At 50C, 0.3 M sulfuric acid attacksTiNi at 3 mpy; 3.0 M, at 670 mpy(589)(1063)(2232).

Corrosion in Biological systems

In vivo studies of TiNi in rats and in dogs show no signs of incompatibility. Test Reports onTiNi in diverse biological systems can be found in references (2958 to 2999).

References

1063J.M.Macki, K.Terada, R.L.KochenA n Evaluation Of The Cryofit Tube Joining System In Selected Plutonium Chemical ProcessingSolutionsDow Chemical U.S.A.,Golden Colorada1973English

1130K.N.Melton, O.MercierThe Mechanical Properties Of Niti-Based Shape Memory AlloysActa Metallurgica,Vol.29,P.3931981EnglishNi-Ti, Ni-Ti-Cu, And Ni-Ti-Cu-Fe Alloys Are Prepared, Tensile Tested And 6 Impact Tested. Fracture Energies Are Minimum Just Below Md. Martensite Plastic Yield Is Higher Than TheAustenitic Yield. Y ield Ratio Was The Greatest In A Nickel-Rich Binary (7:1). S tress Rates AreMeasured And The Latent Heats Calculated.

2232Y.Suzuki, K.Takayanagi, Y.Fujii, T.Kuroyanagi, T.TsutsuiApplication Of Faedic-Nt (Improved Niti Alloy) To Nuclear Reactor Pump Components Titanium'80,Sci. And Tech.,Vol.1,P.4971980EnglishNi-Ti Is Alloyed With 1.6% Fe And 1.8% Mo To Improve High Temperature Strength, Abrasion, AndCorrosion Resistance. C orrosion Data Is Several Solutions Is Given. E rosion Is Second Only ToStellite. T ensite Strength Is Constant Up To 300C.

2233A.Negishi, K.Takayanagi, M.IkedaCorrosion And Wear Resistant Nickel AlloyU.S.Patent 3,660,0821972English

2930Guangming, L.; Jinxiu, Z.; And Laizhong, L.Study Of Snap-Acting Two Way Shape Memory Effect In Niti AlloyXiyou Jinshu/Rare Metals V8 N3 July 1989 P39-411989EnglishS nap-Acting Transformation And Snap-Acting Two Way Shape Memory Effect Have Been ObtainedIn Ni ti Alloy Using The Constrained Effect Of Stress On The Driving Force Of Twsm Element. TheTwsm Strain Of The Snap-Acting Element Made Of Ni51 Ti 49 Alloy Finishes Abruptly At An AcertainTemperature Without Any Additional Mechanism, Within An Interval Less Than 1 Ms. AThermodynamic Model Is Presented To Account For These Observations.

2938Tony ThompsonH2 & TiniPrivate Notes/Phone Conversation1988English* Ni-Ti-Fe In Water Plus Hydrogen At 300 C* Tony Thompson* 1988* Ni-Ti-Fe* Hydrogen*Embrittlement

2939P. ValemboisN2h4 And Mon-3General Electric Private Publication1991English* Raychem Cryofit Sleeves N2h4 And Mon-3 Compatibility* P. Valembois* 1991* Ti-Ni-Fe Corrosion

2941Tom Borden, Jack HarrisonLiquid Metal CorrosionMemo From Jack Harrison1992English* Niti Corrosion By Liquid Metals* Tom Borden* 1992* Niti* Aluminum* Mercury* Corrosion

2942Schweiso, SchwinghamerLiquid And Gaseous Impingement Of Oxegen On TiniLetter From National Aeronautics And Space Administration1971English* Niti Sensitivity To Liquid And Gaseous Oxegen* R.J. Schwinghamer* 1971* Ni-Ti-Fe* Oxidation*Oxygen

2944Clyde LofdahlCryofit Tunneling CorrosionRaychem Memos1970English* Grumman 5% Nacl Spray And So2 Test Of Cryofit Assembly* J. Combs; J.D. Harrison; ClydeLofdahl* 1971* Cryofit * Corrosion * Pitting * Crevice Corrosion * Ni-Ti-Fe

2945John GuadasCorrosion Of TiniDepartment Of The Navy1973English* Properties Of Modified Nitinol Alloys* J.P. Guadas, D.A. Davis & F.J. Gomba* 1973* Corrosion* Ni-Ti-Cr* Ni-Ti-Mo* Ni-Ti-Fe

2946Ralph NelsonMedtronic RingsRaychem Memo1980English* Cryofit Cracking In Iodine Polyvinyl Pyridine* Ralph H. Nelson* 1980* Crack Growth* Corrosion*Couplings* Ni-Ti

2948Ralph NelsonCardiac Pacemakers, Inc.Raychem Memo1977English* Test failure of cryocon contact* Ralph H. Nelson* 1977* crevice corrosion* Ni-Ti-Fe* Medical

2949Barry Wallace & John ChenAstm G42-75t Charging With Tini With H+Personal Notes From J.D.Harrison1978English* Hydrogen Charged Cryofit Couplings* J.D. Harrison* 1978* Embrittlement* Hyrdogen* Ni-Ti-Fe

2950Pitting- Corrosion Failure Of Type 304 Stainless Steel Aircraft Hydraulic Tubes In A MarineAtmosphereAsm Metals Handbook 8th Ed. Vol. 101975EnglishStainless SteelCorrosionPittingTubes

2951Ronald W. Schultz And David E. ThomasCorrosion Of TitaniumAsm Metals Handbook 9th Ed. Vol. 13 P. 6871987English* Titanium* Methanol* Corrosion* Pitting

2952John D. HarrisonShell/Aberdeen Methanol TunnelingPersonnal Notes1980English* Corrosion* Couplings* Pitting

2953John D. HarrisonHarbor Island Cryofit FailurePersonnal Notes1979English* Corrosion* Couplings* Pitting

2956John SimpsonHydrogen Charged Tensile SamplesMemo

1983English* Embrittlement* Hydrogen* Mg Shift* Tensile Properties

2957Mary QuinCrofit In Hcl SolutionRaychemMemo1982English* Corrosion* Couplings* Pitting

2959Y. Arima, M. Ohata, K. Ohmori, K. Kitamura, S. Nakamura, H. Natori, Y. SezaiExperimental Study On Rib-Fixation Pin Using Shape Memory Alloy - Histological Evaluation OnImplantation StudyJpn. J. Artif. Organs, 18/1, Pp. 179-1821989EnglishT he In-Vivo Implantation Study Was Conducted To Evaluate The Histocompatibility Of ShapeMemory Alloy In A Living Body. K irschner's Wire Was Used As A Control, And Pins Were ImplantedSubcutaneously In The Dorsal Region Of Two Dogs. 2 Weeks, 4 Weeks, 8 Weeks, 4 Months, And 6Months After The Implantation, The Pins Were Removed With The Surrounding Tissues AndEvaluated Histologically. At 2 Weeks, The Inflamatory Reaction Was Strong In Both Groups, At 4Weeks The Capsules Were Formed, And After 8 Weeks, Neither Inflamatory Nor Foreign BodyReactions Were Observed In Either Group.

2960C. Dunlap, S.K. Vincent, B. BarkerAllergic Reaction To Orthodontic Wire: Report Of CaseJada, Vol. 118, April, Pp. 449-4501989English"A Teen-Aged Female Patient Developed Painful, Red, Macular Lesions On The Oral Mucosa. T heOnset Of Symptoms Coincided With The Placement Of An Orthodontic Wire In Maxillary Arch. Biopsy Showed Changes Typical Of Allergic Contact Stomatitis And Removal Of The Wire Resulted InComplete Clearing Of Lesions Within 4 Days"" Pat ient Had A History Of Allergy To Jewlery...""I nThis Case, The History And Clinial Lesions, When Coupled With The Histopathologic Changes AndResponse To Treatment, Make A Convincing Argument For Allergic Contact Stomatitis Caused ByNickel. Tit anium Cannot Be Completely Excluded As The Allergen In This Patient. Howev er, It DoesNot Seem Likely Because Most Jewelry Does Not Contain Titanium, And Titanium Allergy, To OurKnowledge, Has Not Been Reported."

2961M. Prince; E. Salzman; F. Schoen, A. Palestrant; M. SimonLocal Intravascular Effects Of The Nitinol Wire Blood Clot FilterInvestigative Radiology, Vol 23, No. 4, Pp 294-3001988EnglishIn Two Filters, About 1 To 3 Mg Of Nickel And Titanium, Representing Less Than 1% Of The Filter,Were Lost By Corrosion In Four Years. T he Normal Daily Dietary Intake Of Ni Is About 0.5 Mg. TheReccommended Safe Level Of Exposure To Nickel From Intravenous Fluids Is Less Than 7% Of TheTotal Body Burden Of Nickel Or 35 Micrograms Per Day For A 70 Kg Adult. D uring A Four-YearPeriod This Amounts To 51 Mg Or About 30% Of All The Nickel In The Filter. T he Authors ConcludeThat Exposure To Nickel From The Filter Is "Well Within Acceptable Limits"

2962G. Rondelli; B. Vincentini; A. CigadaShape Memory Alloy As A Human Body Implant MaterialThird World Biomaterials Congress, Kyoto, Japan, Aprill 21-25, Paper #2p-39, P.1691988English"Pitting Potentials Obtained By Potentiodynamic Tests Are Noticeably Higher Than Those ObtainedFor Stainless Steels. However, In The Potentiostatic Scratch Test The Stainless Steels Exhibit BetterPerformances. Also In The Astm Test The Niti Alloys Showed A Localized Corrosion ResistanceSlightly Lower Than The Stainless Steels""On The Whole It Seems That The Niti Alloys Could BeUtilized For The Orthopaedic Devices Only In Absence Of Metal-Metal, Metal-Ceramic, And Metal-Plastic Couplings That Are Typical Sites For The Onset Of Crevice Corrosion"

2963Y. NakayamaThe Biological Reactions Of Several Orthopaedic Implant Alloys In RatsThe Third World Biomaterials Congress, Kyoto, Japan, Paper #5c1-33, P.4951988EnglishNiti, 316l Stainless Steel, Co-Cr-Mo, Ti-6a1-4v, Ti-15 Mo-5zr-3a1 And Pure Nickel Implants (3mmDia. By 7mm Long) Were Placed In Quadriceps Muscle Belly And Femoral Condyle Of Male Rats.Animals Were Sacrificed At 1,3,6 Months."There Were No Systemic Effect Or Statistically MeaningfulDifference Among Body Weight Gain Ratio In Alloys Except Nickel. Spontaneous Death Occurred InNickel Case Around 6 Month. Massive Tumor-Like Granulation Formulation And Cystic Change WereSeen Around The Quadriceps Muscle Implantation Site. Body Weight Gain Ratio Of Nickel Was LowComparing To Other Alloys""Fibrous Layer Was Formed In All Alloys Except Nickel And The OrderOf Thicknesses Was Compatible With The Order Written In 1) No Constituent Metal Dissolution WasNoticed In Niti Or Sus316l Or Two Titanium Alloys...The Order Of The Thickness Of Fibrous LayersFormed Around Implant Allys In Bone And Muscle Is Compatible With The Order Of CorrosionResistance Of Them."

2964J. Geis-Gerstorfer, Heiner WeberCorrossion Resistance Of The Implant Materials Contimet 35, Memory, And Vitallium In ArtificialPhysiological FluidsInt. J. Oral Maxilliofacial Implants, 3: 135-1401988EnglishThe Linear Polarization Method Has Been Used To Demonstrate The Influence Of DifferentElectrolytes On The Corrosion Behavior Of Ti, Ni-Ti, And Co-Cr-Mo. Results Revealed MinimalCorrosion Tendency To Ti; Co-Cr-Mo, And Especially Ni-Ti, Showed Rapid Breakdown Of PassivityWith Increasing Chloride Concentrations In Unbuffered Solutions And Little Differences In BufferedSolutions. Niti Supplied By Krupp Medizuntechnik Gmbh.

2965Yang Pei-Jun, Zhang Yan-Feng, Ge Mao-Zhi, Cai Ti-Dong, Tao Jin-ChunInternal Fixation With Niti Shape Memory Metal Alloy Compressive Staples In Orthopedic SurgeryChinese Medical Journal, 100 (9), 712-7141987EnglishIn 8 Patients (Of 51 Cases) Where Staples Were Removed In 3 To 26 Months, No Obvious ForeignBody Reactions Could Be Found. No Details Provided.

2966H. Hamanaka, H. Dori, T. Yoneyyama, O. Kohno, I. MiuraNo Title.Reports Of Institute For Medical And Dental Engineering, 21, P. 1-71987EnglishThe Authors Have Been Studying Dental Uses Of These Alloys. In This Paper, Corrosion ResistanceOf Cast Ni-Ti Alloys Were Studied On Electrochemical And Immersion Test.Ni-Ti Alloys ShowedHigher Break Down Potential In Anodic Polarization Curves Than Those Of Ni-Cr And Co-Cr AlloysOn The Market. The Amount Of Ni Cations Dissolved From Ni-Ti Alloys In 0.9% Nacl Solution Is ByFar Lower Than Those From Dental Alloys Now In Clinical Uses. There Seemed To Be No ProblemFor The Dental Application Of The Cast Ni-Ti Alloys.

2968Tan Shusung, Qian Dongfan, Chu Youyi, T. KoResearches And Applications Of Shape Memory Alloys In ChinaProc. Of Intl. Symp. On Shape Memory Alloys, Guilin, China, Pp. 1-111986EnglishReferences Other Work In China On Simulated Corrosion Tests, Toxicity In Vitro, HistolgicalObservations, And Analysis Of Free Ni Content, No Test Longer Than 2 Years (4 Dogs)As To TheQuestion Of Carcinogenisis..., Only From Long Term Embedment Experiment Can A Judgement BeStemmed

2967Hiroshi Kimura, Tajii SohmuraSurface Coating On Tini Shape Memory Implant AlloysJ. Osaka Univ. Dent. Sch.,Vol.27, 211223, 19871987EnglishCorrosion Resistance In Tini Shape Memory Alloys Which Is Utilized As A Dental Implant WasStudied In 1% Nacl Solution By Means Of Anodic Polarization Measurement. In Most Of Specimens,Current Dentistry Increased At About 1200mv, But In Some Specimens, An Abrupt Increase InCurrent Dentistry Was Observed At Low Potential Such As 500-600 Mv, And This Was Found ToOriginate From The Formation Of Pitting. In Such Case, Dissolution Of Ni In A Living Body IsDoubtful.In Order To Prevent The Dissolution At Low Potential, Surface Coating By Ticn, Tin AndOxide Film Were Attempted. By Coating, The Amount Of Current Dentistry Decreased And NoAbrupt Increase In Current Were Observed In Any Case. However, In Ticn Coating, The CoatingLayer Was Easily Peeled Off By Strain Upon Shape Memory Effect. In The Case Of Tin Coating,Cracks Were Formed Especially In Compression Side And Abrupt Dissolution Was Observed. OnThe Other Hand, By Oxide Film Coating, Abrupt Dissolution Was Suppressed Even After PlasticDeformation Upon Shape Memory And Recovery Process. Oxide Film Coating Is Considered ToImprove Corrosion In Tini Shape Memory Alloy.

2969Xue Miao, Jia WeitaoApplications Of A Niti Shape Memory Alloy To Medicine And DentistryProc. Of Intl. Symp. On Shape Memory Alloys, Guilin, China, Pp. 411-4151986EnglishReferences Earlier Work By Xue Miao (1982). "Compared To 316l Stainless Steel, Niti Alloy Is ABetter Anti-Corrosion Biomedical Alloy." Regarding Toxicity Test In Vitro " Cells Grew Well On TheSurface Of Alloy."

2970Zhang Xufeng, Liu Guolin, Yuen Jinrui, Zao Qi, Yi Lin, Hu Ziping, Zhou Shouli, Hue JieA Study Of Shape Memory Alloy For MedicineProc. Of Intl. Symp. On Shape Memory Alloys, Guilin, China, Pp. 416-4201986EnglishResults Of A Simulated Corrosion Study (Using Artificial Saliva, Artificial Sweat, Hank's PhysiologySolvent 1% Nacl, Lactate Solvent , .05% Hcl And 0.1% Nas) Are Reviewed. After 72 Hours NoChange In Weight Was Noted (+/- .001 G). Niti Was Rated With 316l Stainless Steel To Be In GradeA For Anticorrosion (Soviet Union Standard)No Tumor-Like Hyperplasia Were Noted After ThreeMonths Using Four Rabbits Containing Niti And 316l Inserts Near Their Backbones.

2971J. Haasters, G. Bensmann, A. PonApplications Of The Memory Alloy Niti As Implant MaterialMaterials Sciences And Implant Orthopedic Surgery. 117-1241986English40 Rats Tested (6, 12, 18, And 24 Weeks) With Cylinders And Rings (Internal Tissue Is Inactive AndAt Rest) No Corrosion Found. Observed Typical Foreign Body Reaction (Fibrocytes, Lymphoytes)Looked Same Compared To Conventional Material Specimens Also Tested.

2972P.J. Yang, Y.F. Chang, M.Z. Ge, T.D. Cai, J.C. TaoInternal Fixation With Niti Shape Memory Alloy Compressive Staples In Orthopedic SurgeryProc. Of Shape Memory Alloys, China Academic Publications, 438-4371986English51 Cases Reviewed Follow-Up Exams After 2 Years Showed No Sign Of Inflammation. EightPatients (>20 Months With Niti Staples) Showed No Foreign Body Reaction Based On HistologicalStudies

2973Zhao Dinglin, Zhang Weiming, Xu Yinkan, Tu KaiyuanStudy And Clinical Application Of The Cervical Intervertebral Artificial JointProc. Of Shape Memory Alloys, China Academic Publications, 433-4371986EnglishIn 32 Cases, 30 Were Followed Up For 14 To 48 Months. No Sign Of Localized Tissue Death.

2974K.R. Dai, R.S. Wu, J.X. Yuan, Y.H. Sun, H.B. Yang, W.Q. Hong, S.C. Shen, L.Y. LiuOrthopedic Applications Of Niti Shape Memory AlloyProc. Of Shape Memory Alloys, Pp. 430-4321986English16 Cases With 6 To 48 Month Follow Up. No Tissue Reaction.

2975Bruno Vincentini, Gianni Rondelli, Alberto Cigada, Giovanni TurisiniCorrosion Behavior Of A Nickel Titanium AlloyProc. Of Sma '86, China Academic Publs., Pp.447-4541986EnglishIn This Paper 3 Alloys Have Been Examined: Ti 6al 4v, Niti (50% At Ni) And Aisi 316l. In AcidEnviornments (0.5 M Sulphuric Acid) The Niti Alloy Behaves Like The Ti 6al 4v (Only PassiveCurrents Are Higher For The Former), While Aisi 316l Has The Lowest Passivation CurrentDensities.The Ti 6al 4v Alloy Shows The Best Resistance To Localized Corrosion (Pitting AndCrevice). Niti Exhibits A Very High Pitting Potential In The Potentiodynamic Tests Performed InChloride Containing Solution. However, The Aisi 316l Has A Higher Capacity To Repair The PassiveFilm Broken Down Lo

2976B. Vincentini, G. Rondelli, A. Cigada, G. TurisiniCorrosion Behavior Of A Nickel Titanium AlloyChina Academic Publs. Pp.447-4541986EnglishThe Resistance To Pitting Corrosion As Determined By The Potentiodynamic Tests In 3.5% Nacl,Decreased In Th Eorder: Ti 6a1 4v ..Niti.Aisi 316l. The Ti 6a1 4v Alloy Shows The Best ResistanceTo Localized Corrosion (Pitting And Crevice). Niti Exhibits Very High Pitting Potential In ThePotentiodynamic Tests Performed In Chloride Containing Solution. However, The Aisi 316l Has AHigher Capacity To Repair The Passive Film Broken Down Locally And As A Consequence It GivesBetter Performances Than The Niti Alloy In The Potentiostatic Measurements (Scrat Test; Astm F 46-81 Test) Lastly, Our Results Pointed Out, For Our Niti Alloy, A Pitting And Crevice CorrosionResistance Better Than Those Reported In The Literature.As A Whole The Niti Alloy Offers APromising Corrosion Behavior View Of Potential Applications As Implant Material, Even ThoughFurther Corrosion Studies Are Envisaged.

2977J. Takahshi, M. Ozazaki, H. Kimura, N. Horasawa, M. Ito, S. TakahashiSuperelasticity And Released Metal Concentration Of Ni-Ti And Ni-Ti-Cu Alloys CastingsJournal Of The Japanese Society For Dental Materials And Devices. Vol.5 No.51986EnglishReleased Ni Concentrations Of Both Ni-Ti And Ni-Ti-Cu Alloys Were Lower Than Those Of Dental Ni-Cr Alloys. These Alloys Were Exposed At 37c For One Week In Three Solutions: Ringers Solution,1.0 Lactic Acid And 0.055 Hcl. Niti Exhibited A Release Of 0.17, 0.95 And 2.90 Mg/Cm2 While Ni Cr(L) Exhibited 18.5, 11.1, And 398 Mg/Cm2 And Ni Cr (Ll) Exhibited 4.90, 0.70 And 47.4 Mg/Cm2 Nicr(L) Is 75.5 Weight % Ni, 19.5% Cr And 2.4% Mo And Nicr (Ll) Is 67.7 Weight % Ni, 16.3% Cr, 3.6%Mo, 5.6% Mn, 2.6% Cu, 2.0% Co And 2.6% Al.

2978Paul Pang-Fu Kuo, Bei-Chun Yang, Yan-Feng Zhang, Ke-Rong Dai, Yue-Fei YuClinical Use Of Niti Shape Memory Alloy In Orthopedic Surgery-A Preliminary ReportProgress In Artificial Organs, 1105-11071985English"No Obvious Local Reactions Nor Corrosion Of The Staples And Screws" Removed Postoperatively.Also Ti-Ni Cubes Of 1mm3 Embedded In Thigh Muscles Of 60 Dogs For 10 Months Showed NoObvious Evidence Of Reaction.

2979

2980A. EdwardsApplication Of Electrochemical Techniques To The Prediction Of Enviornmental Effects On TheCorrosion Behaviour Of A Niti AlloyMarine Corrosion % Fouling Vol.1 Sixth Intem Congress1984EnglishPotentiostatic Techniques Have Been Used To Study The Effects Of Changes In Ph And ChlorideConcentration To Seasalt Solutions On The Corrosion Behavior And, In Particular, Pitting CorrosionResistance Of A 52 Ni, 45 Ti And 3 Fe Alloy. The Alloy, Known To Be Susceptible To CreviceCorrosion In Seawater, Was Also Found To Be Susceptible To Pitting Corrosion In AcidifiedConcentrated Seasalt Solutions And Subject To Rapid Uniform Corrosion In Hydrochloric AcidSolutions.

2981Yang Pei-Jun, Y.F. Zhang, M.Z.KuhThe Use Of Niti Shape-Memory Alloy Staples For Internal Fixation Of FracturesChinese Journal Of Ortho., 3, Pp. 137-1401983ChineseNo English Abstract Available. Translation Indicates 18 Case Studies On Limbs, Joints, Palms, AndAnkle Bones In 18 Patients. Alloy Took Less External Fixation Time With No Sign Of Loose FixationOr Swollen Soft Tissue.

2982N.K. Sarkar, W. Redmond, B. Schwaninger, A..J. GoldbergThe Chloride Corrosion Behavior Of Four Orthodontic WiresJournal Of Oral Rehab., Vol. 10, Pp.121-1281983English"Potentiodynamic Cyclic Polarization Of Four Orthodontic Alloys (Wires), Namely Permachrome,Elgiloy, A 8-Titanium Alloy, And Nitinol In A 1% Nacl Solution Within -500 Mv And +300 Mv (Sce)Indicated The First Three Alloys To Be Passive Whereas Breakdown Of Passivity Was Observed OnNitinol. The Sem Examination Of The Pre-And Post Polarized Alloy Surfaces Provided EvidenceWhich Was Consistant With The Elctrochemical Measurements, In That The First Three AlloysExhibited No Appreciable Corrosion Damage Whereas Pitting Corrosion Was Observed OnNitinol"This Work Contradicts Work Of J.W. Edie, 1981. See Abstract

2983K.R. DaiThe Use Of Compression Staples On Niti Shape Memory Alloy In Orthopedic SurgeryChinese Journal Of Orthopedics Vol. 21, Pp. 343-3451983EnglishReferences Work By Castleman Et. Al And Xue Et Al. Xue Experiments (1980) "Proved" That Niti HadGood Corrrrosion Resistance To Man-Made Sweat, "Hank" Solution, Nacl, And Nas. Also After 10Months Implantation In Bone And Skin, There Was No Sign Of Corrosion Or Tissue Color Change.Tissue Restoraion Was Short And Tissue Reaction Was Light.

2984Xue MiaoFundamental Medical Research Of Nickel-Titanium Memory AlloysChinese Journal Of Biomedical Engineering Vol. 2, No. 1, Pp.28-331983EnglishDescribes An Experiment On 60 Female Rats; 30 Rats Had Subcutaneous Implantations (4mmDiameter By 1mm Thick) And 30 Rats Had Bone Interior Implantations (2mm Diameter Balls). Niti(49-51) Was Compared To 316l Stainless Steel And Carbon Fiber Reinforced Carbon (Cfrc). RatsWere Sacrificed At 1 And 2 Weeks; 1,2,3,4,5 And 10 Months. "Nickel-Titanium Memory AlloysDiscolor Slightly When Placed In A Simulated Body Fluid Medium; However, This Phenomenon Is NotDetected When Implanted Inside An Animal. Experimental Results Show That After 10 Months OfImplantation In The Tissues And Inside The Bones Of Rats, There Is No Damage To The LocalTissue. Inflammation Is Slight, Tissue Recovery Time Is Short, There Is No Indicaton OfDiscoloration, Corrosion, Or Cellukar Toxicity, The Biotolerance Is High, And Biodegeneration Is Low.During The Observation Period Equivilant To 2/5 Of The Life Span Of The Specimen, There Is NoIndication Of Localized Neoplasm. Compared To Stainless Steel And Carbon Fiber ReinforcedCarbons, Nickel-Titanium Memory Alloys Have A Better Biocompatibility"

2985U.E. Pazzaglia, C. Minoia, L. Ceciliani, C. RiccardiMetal Determination In Organic Fluids Of Patients With Stainless Steel Hip ArthroplastyActa. Orthop. Scand. 54, 574-5791983EnglishNi Levels In Blood, Plasma And Urine, Manganese Levels In Blood And Urine, And Chromium LevelsIn Plasma Were Significantly Higher In Hip (10-13 Year Old) Prosthese Population Thaaa In A ControlGroup."The Increased Level Of Metal Ion Is Well Below The Threshold Of Metal Toxicity For Each OfThe Various Metals. The Release Of Metal Ions By Stainless Steel Metal-Plastic Prothesis Does NotSeem To Cause Sensitization Even After A Prolonged Period Of Time"

2986Frederick J. Krummer, Robert M. RoseCorrosion Of Titanium/Conbalt Chromium Alloy CouplesJournal Of Bone And Joint Surgery, Vol. 65-A, No.8, October 19831983EnglishThe Stability And Gradual Reduction Of The Current For The Titanium Couples Are Indicitave Of TheFormation Of A Stable Passive Film. The Behavior Of The Stainless Steel Cobalt-Chromium AlloyCouple Indicates That It Was Not Stable And Would Continue To Corrode; Thus That The Use OfDisimilar Metals In Orthopedic Implants Should Be Approached With Great Caution.

2987Gunter Bensman, Frank Baumgart, Jorg HaastersNickel-Titanium Osteosynthesis ClipsMedical Focus, March, 19831983EnglishTissue Covering The Implant Which Was Obtained On Removal Of The Clips Was Subjected ToHistological Examination. Inflammatory Rejections, Increased Blood Supply Or Other RejectionMechanisms Were Not Observed. Contamination Of The Examined Tissue With Memory MetalAmounted To Between 6 And 10 Months. Compared With The Preceding Histological InvestigationsOn Animals, This Permits The Conclusion That The Memory Implants Did Not Produce AnyPathological Response In The Patients Observed And Examined.Several Memory Clips Which HadBeen Implanted For Up To 1.6 Years Were Examined Following Removal By Surgery. MacroscopicStudy Showed All The Clips To Have A Uniform Appearance With Bright Metallic Surface. SlightScratches Are Attributable To Mechanical Damage During Implantation And Extraction. No CorrosionWas Observed On Visual Inspection. Results Of Microprobe Spectrometery Established MoreoverThat No Change Had Occured In The Chemical Composition On The Surface Of The ImplantsCompared With The Core Material. Accordingly, The Material Used For The Clips May Be AsAdequately Resistant To Corrosion.

2988G. Bensmann, F. Baumgart, J. HaastersOsteosynthesis Clamps Made From Niti : Manufacture; Preliminary Tests, And Clinical UseTech. Mitt. Krupp, Forsch-Ber. 40, Pp. 123-1341982EnglishBreif Includes Review Of Histologic Examinations Performed On Tissue After Removal Of MemoryClamps From Human Feet After 6 To 16 Months. No Inclusions Of Inflammatory Reactions Or OreignBody Reactions Seen. Comparison Of Connective Tissue Membranes Associated With MemoryImplants And With Other Metal Implants Appear Basically The Same. They Conclude That TheMemory Implants Showed No Pathological Reactions In The Patients Which Were Studied.

2989K. Kuehn, F.W. Sunderman, Jr.Dissolution Half-Times Of Nickel Compounds In Water, Rat Serum, And Renal CytosolJournal Of Inorganic Biochemistry, 17, 29-391982English17 Nickel Compounds Were Incubated In Water , Rat Serum, And Rat Renal Cytosol For 72 Hours At37 Deg. C. Concentrations Of Dissolved Nickel Were Analyzed By Electrothermal Atomic AbsorptionSpectophotometry, And Dissolution Half-Times (T50) Were Computed By The Weibul Equation. 11Of The Nickel Compounds (Ni, Bnis, Amorphous Nis, Ani3s2, Nise, Ni3se2, Nite, Nias, Ni11as8,Ni5as2, And Nifes4) Dissolved More Rapidly In Serum Or Cytosol Than In Water. 4 Of TheComppounds (Nio, Nisb, Nife Alloy, And Nitio3 (Often Seen On Niti Surfaces)) Had No DetectableDissolution In Any Of The Media ( I.E. T50> 11 Yrs.) These Findings Suggest That In Vitro DissolutionHalf-Times Of Nickel Compounds May Be Used To Predict Their In Vivo Excretion Half-Times, SinceThe Dissolution Process Is Rate-Limiting To Their Metabolism And Excretion.

2990G. Bensmann, F. Baumgart, J. HaastersApplication Of Memory Alloy Niti As Implant MaterialTrans. Of 8th Annual Meeting Of Soc. Of Biomaterials, Vol. V, P.901982EnglishHan Vistar Rats Implanted With Niti On Both Sides For 6, 12, 18, And 24 Weeks For Tissue ReactionTests. "No Signs Of Corrosion Were Found On Metal Specimens On Their Removal"Histologically,Inflammatory Reactions Were Apparent Around The Foreign Body, But No Giant Cells Induced By ItsPresence Were Found. For Comparison, Specimens Of The Same Shape And Of ConventionalProsthesis Material Were Implanted In The Same Animal. Here The Same Reaction Was Visible InThe Connective Tissue Around The Foreign Body. Capular Thickness Measurements Showed AClear Diminution As The Implantation Period Increased.To Investigate The Behavior And Function OfNiti Implants, Niti Jaw Plates, For The Osteosynthesis Of A Simulated Fracture Of The Lower Jaw,And Clamps Were Implanted In Minipigs, And Spacers For Stiffening The Spinal Column In Sheep.The Operations Were Successfully Carried Out And In No Case Were Harmful Tissue ReactionsFound.

2991L.S. Castleman, S.M. MotzkinThe Biocompatibility Of NitinolBiocompatibility Of Clinical Implant Materials, Ed. D. Williams, 129-1541981EnglishReferences 92 Articles. Discusses The Biocompatibility Of Nickel, Titanium, And Niti

2992J.W. Edie, G.F. Andreasen, M.P. ZaytownSurface Corrosion Of Nitinol And Stainless Steel Under Clinical ConditionsThe Angle Orthodontist, Vol. 51, No. 4, October, Pp. 319-3241981EnglishRecent Papers Raise Concern That Nitinol Wire Had Been Reported To Have Greater CorrosiveTendency That Stainkess Steel Wire (Ss) During Anodic Dissolution. This Paper Questions WhetherThese Lab Experiments Relate To Potential Corrosive Experience In Clinical Service. The StudyAssesses Surface Characteristics By Topographical Appearance With Sem, Qualitative ChemicalContent With Eds, And Relative Quantitation Of Oxygen Content With Wds. "Eleven Nitinol AndEleven Stainless Steel Wires Were Retrieved After Clinic Services For Periods Ranging From One ToEight Months." Comparisons Were Made To Unused Nitinol And Ss Wires And To Nitinol SubjectedTo Anodic Dissolution For Two Minutes. Unused Nitinol Wires Show Large Variatons In SurfaceTextures When Compared To Ss Wires" Because Of These Variations Of Unused Nitinol Surfaces, ItIs Difficult To Assess The Degree Of Corrosion Existing On The Surfaces By Visual Inspection.However, No Pits Or Surfaces Typical Of Anodically Dissolved Wires Were Observed On EitherNitinol Or Stainless Teel Wires. Because Of Wire Surface Variability, It Is Difficult To Make AbsoluteAssessments Of Corrosive Action Without Direct Comparison Of Before And After ServicePhotographs. The Nitinol Wires For Which That Was Done Had Practically Identical Surface FeaturesAnd No Obvious Corrosion Products. In Ccnclusion, The Results Reported Here Suggest That ThereIs No Reason To Believe That Nitinol Wires Are Any More Subject To Corrosion Than Stainless SteelWires In An Enviornment That Is Typical Of Clinical.

2993K. Speck, A. FrakerAnodic Polarization Behavior Of Niti And Ti-6a1-4v In Simulated Physiological SolutionsJ. Of Dental Research, Oct. 59, No. 10, 1590-15951980English"This Study Has Confirmed Results Of Other Investigations Which Show That Titanium And Its AlloysAre More Corrosion Resistant To Simulated Body Fluids Than Are 316l Stainless Steel, The Co-Cr-Mo Alloy, And The Co-Ni-Mo Alloy. Other Conclusions Of This Study Are Summarized. Although TheBreakdown Potential The Amino Acid Is Lowered By The Presence Of The Cysteine, This BreakdownStill Is Comparable With Or Higher Than That Of The Other Non-Titanium Metals Used In This Study"

2994M. Simon, R. Kaplow, E. Salzman, D. FreimanA Vena Cava Filter Using Thermal Shape Memory AlloyRadiology, Vol. 125, No. 1, Pp. 89-941977EnglishThe Study On 16 Dogs Primarily Focused On Effectiveness Rather Than Biocompatibiliy. "NoThrombus Was Observed On The Exposed Surface Of The Filter Wire In These Cases."

2995A. Gaechter, J. Alroy, G.B.J. Andersson, J. Galante, W. Rostoker, F. SchajowiczMetal Carcinogenisis: A Study Of The Carcinogenic Activity Of Solid Metal Alloy In RatsJ. Bone Joint Surgery., A59, 622-6241977EnglishThe Carcinogenic Activity Of Seven Metallic Alloys Was Studied By Implanting Solid Rods Of EachAlloy In The Gluteal Muscles Of Sprague-Dawley Rats Which Were Killed After 24 Months. WhenThe Number Of Tumors In These Rats Was Compared With The Numbers In Rats Not Operated On,In Rats Which Had A Sham Operation, And In Rats Implanted With Silastic Rods, No StatisticallySignificant Differences In These Incidences Of The Tumors In The Several Groups Were Found.ThisIs Not Directly A Niti Study: However, Mp35n, An Alloy Which Contains A Large Percentage Of Ni (33To 37%) With 20% Cr, 10% Mo, And 35% Co, Was Included In This Test.Article Concluded That TheResults Of This Study Show That Solid Implants Of 7 Different Metallic Alloys Commonly Used InOrthopedic Surgery Do Not Constitute A Major Carcinogenic Hazard When Implanted In The MuscleOf Rats; However, The Authors Point Out That Physical Characteristics Of The Implants (Rods Vs.Disc Vs. Powder) Tissue Type ( Bone Vs. Muscle) Patient ( Rat Vs. Human) Can Play A Role InCarcinogenic Activity.

2996S.M. Motzkin, L.S. Castleman, W. Szablowski, V.J. Bonawit, F.P. Alicandri, A.A. JohnsonEvaluation Of Nitinol Compatibility By Cell CultureProc. Fourth New Engl. Bioengr. Conf., 301-3041976EnglishNiti And Titanium Significantly Reduce Cell Growth After Four-Day Culture Tests. Niti Has A LessDeleterious Effect Than Does Titanium.Tissue Culture Studies Of Human Kung Fibroblasts ShowedNitinol Somewhat More Reactive Than 316l Ss And Co-Cr Alloy, But Nitinol Is Comparable Or LessActive Than Titanium. No Evidence Of Corrosion.The Authors Conclude That Niti Is Worthy OfFurther Investigation.

2997L.S. Castleman, S.M. Motzkin, F.P. Alicandri, V.L. Bonawit, A.A. JohnsonBiocompatibility Of Nitinol Alloy As An Implant MaterialJ. Biomed. Mater. Res., 10, Pp. 695-7311976EnglishDetails Outlined In 1981 Castleman ReferenceIn Dogs Containing Nitinol And Co-Cr Alloy ImplantsFor Periods Of 3, 6, 12, And 17 Months, There Were No Signs Either Of Generalized Or Of LocalizedCorrosion That Could Be Attributed To A Reaction Between The Metallic Surfaces And TheImmediately Adjacent Tissue.Gross Clinical And Radiological Observations Indicated That There WasNo Discernible Difference Between Sham-Operated Dogs And Dogs Containing Nitinol And Co-CrAlloy Implants For The Aforementioned Time Periods.There Was No Significant Difference In TheHistological Observation Of Bone And Tissue Adjacent To The Implants, Whether Made Of Nitinol OrOf Co-Cr Alloy, And Those Made On Corresponding Bone And Tissue Removed From ShamOperated Dogs.

2998D. Cutright, S.N. Bhaskar, B. Periz, R. Johnson, G. CowanTissue Reaction To Nitinol Wire AlloyOral Surgery Vol. 35, No.4, Pp. 578-5841973English55-Nitinol Wire Suture Was Placed Subcutaneously In 45 Rats. The Reaction Of The Tissue To TheNitinol Was Followed For 9 Weeks. The Tissue Reaction Was Minimal At All Time Periods. TheReparative Process Was Initiated Within 1 To 2 Weeks And Formed A Dense, Relatively AvascualrFibrous Connective Tissue Capsule By 5 To 6 Weeks, With Little Change Beyond This Time.WhenCompared To Stainless Steel In Previous Experiments, The Nitinol Was Indistinguishable From TheStainless Steel At Similar Time Periods.Therefore, On The Basis Of The Results In This Experiment,It Appears That 55-Nitinol Histologically Compares Favorably With Stainless Steel And Could BeUsed In The Deep Tissues.

2999J.L. WallaceEvaluation Of The Intermetallic Compound Tini As An Implant MaterialBs Thesis, Polytechnic Institute Of Brooklyn1970English1. Tini Implants Result In An Increase Of Ti And Ni In Surrounding Muscles And Distant OrgansIncluding The Kidney, Spleen, And Liver.2. Histology Results Indicate That Tini Causes A MildReaction In The Tissue Surrounding The Implant And A Necrotic Condition At The Metal-MembraneInterface.3. Tini Performance In Vivi Was Satisfactory Enough To Warrant Further Investigation InHigher Order Animals.

3000E.A. CalvelliTitanium Test PiecesGrumman Aircraft Qc Data1969EnglishN2o4 Nitrogen TetroxideN2h4 HydrazineCryofit CouplingsTiniCorrosion TestStress Corrosion Cracking Of Titanium In Red Versus Green Nitrogen Tetroxide

3001B.H. CarsonThe Use Of Cryofit Fittings For Space Vehicle Plumbing SystemsLockheed Manufacturing Research Investigation1974EnglishLockheedN2H4 HydrazineTiniTitaniumStainless SteelAluminumCorrosion Test

3002Chas. R.F. Smith I.W.E. RutherN/AArgonne National Laboratory Correspondence1972EnglishArgonne/IdahoNa. Liquid SodiumCryofitTiniCorrosion Test

3003Jack HarrisonComposit Cryofit Union In Chem Plant ServicePersonal Notes1976EnglishHf, Bf3 Hydrogen Flouride, Boron TriflourideTiniStress Corrosion

3004Les HillCryofit CorrosionRaychem Memo1980EnglishHydrogen Chloride GasMarine Cryofit CouplingHms RepulseTiniCorrosionAnne Edwards

3005David J. Larson, Jr.1969EnglishGrummanCadmiumTitaniumTiniLiquid Metal Corrosion

3007Paul HauptlyTest Report - Cryofit In Chromic AcidRaychem Memo1979EnglishChromic Acid & SulphuricccacidCro3 + H2so4TiniCorrosion Test

3008John Land"Nitinol" Cryofit AssemblyLockheed Lab Report1971EnglishLockheedRed Fuming Nitric AcidTiniCorrosion Test

3009Hf-Hno3-H2o RecipiesChemical Polish For TiniDescaling Solution

3010William BuehlerPickleNotes1967EnglishCleaning TiniBright Etch

3011SchulsonTinel In Pressurized WaterMemo1978EnglishAtomic Energy Of CanadaPressurized WaterCorrosion Test

373C.M.Jackson, H.J.Wagner, R.J.Wasilewski55-Nitinol--The Alloy With A Memory: Its Physical Metallurgy, Properties, And Applications--A ReportNasa,Washington D.C.,Sp-51101972English

389P.P.EwaldThe Poststift--A Model For The Theory Of Pole FiguresJ.Of The Less Common Metals,Vol.28,No.1,P.11972English

587B.A.Apaev, B.I.VoronenkoThe Memory Effect In AlloysMetal Science And Heat Treatment,Vol.15,No.1-2,P.241973EnglishGo od General Overview Of Applications And The Memory Mechanism. A lso Shows Yield StressVersus Temperature, And Hardness Versus Ni Content. Mechanical Preconditioning Is Shown, WithRecovery Stress Experiments.

589A.Negishi, K.Takayanagi, Y.FujiiDevelopment And Prospect Of Intermetallic Compound Faedic-NtChemical Economy And Engineering Review,Vol.3,No.5,P.341971EnglishT he Memory Effect Of Ni-Ti Was Suppressed By Adding Mo And Fe. Th e Alloy (Faedic-Nt) HadExcellent Corrosion, Erosion And Wear Resistance.

83W.J.Buehler, F.E.WangA Summary Of Recent Research On The Nitinol Alloys And Their Potential Application In OceanEngineeringOcean Engineering,Vol.1,P.1051968English55-Nitinol and 60-Nit inol Are Compared, Including Fatigue. No n-Magnetic Tools Are Shown; ShapeMemory Is Called By That Name. The Funny 9 Angstr om Structure Is Discribed. M s Is PlottedAgainst Ni; Resistivity Showing The R-Phase Is Shown But Not Recognized. S ome CorrosionProperties Are Shown. B razing With Silver And Welding Are Discussed.

933T.Satow, T.Isano, T.HonmaThe High Temperature Oxidation Of Intermetallic Compound Tini Nippon KinzakuGakkaishi,Vol.38,No.3,P.2421974EnglishThe High Temperature Oxide On Ti-Ni Is Ti02.