Zach Winger Tera e 4718
11
ZACH WINGERTER AE4718 QUESTION 1: Type 1 can occur between 900º to 950º C in gaseous mixtures of air or pure oxygen. Type 2 can be observed from 650 to 750 C when the sulfite gas is present in the gaseous mixture. For type 1, it is initiated from a liquid sodium sulfate on the alloy. Oxygen and sulfur are then removed from this deposit and this causes formation of sodium oxide. Sodium oxide destroys the alloy’s protective oxide layering. This oxide can accelerate formation of nickel oxide and/or aluminum oxide. These products cause the alloy’s original oxide to travel from the inside of the alloy to the sodium sulfate, where they solidify as discontinuous particles. This whole process is unaffected by the gaseous composition. Type 2 also goes through acidic corrosion when in the 900 to 1000 C range. In type 2 the microstructure will have pits that go deep into the alloy. When the sulfite pressures are high, sulfide formation is prominent. Also cobalt ions can diffuse into the liquidus sulfate solution on the alloys surface. They then will harden and cause a discontinuity. This type depends on the S03 pressures.
Transcript of Zach Winger Tera e 4718
-
ZACH WINGERTER AE4718 QUESTION 1: Type 1 can occur between 900 to 950 C in gaseous mixtures of air or pure oxygen. Type 2 can be observed from 650 to 750 C when the sulfite gas is present in the gaseous mixture. For type 1, it is initiated from a liquid sodium sulfate on the alloy. Oxygen and sulfur are then removed from this deposit and this causes formation of sodium oxide. Sodium oxide destroys the alloys protective oxide layering. This oxide can accelerate formation of nickel oxide and/or aluminum oxide. These products cause the alloys original oxide to travel from the inside of the alloy to the sodium sulfate, where they solidify as discontinuous particles. This whole process is unaffected by the gaseous composition. Type 2 also goes through acidic corrosion when in the 900 to 1000 C range. In type 2 the microstructure will have pits that go deep into the alloy. When the sulfite pressures are high, sulfide formation is prominent. Also cobalt ions can diffuse into the liquidus sulfate solution on the alloys surface. They then will harden and cause a discontinuity. This type depends on the S03 pressures.
-
KIC MPAsqrt(m) TENSILE STRNGTH PA E Modulus PACARBON 1.73 3.50E+09 4.00E+11EPOXY 0.65 5.50E+07 2.40E+09PEEK 2.86 8.60E+07 1.10E+09KEVLAR 2.34 3.95E+09 1.31E+11
KIC composite,MPAsqrt(m) strain@fiberfracture sigma star,matrixEpoxy/carbon 0.758 8.75E-03 2.10E+07Epoxy/kevlar 0.819 3.02E-02 7.24E+07Peek/carbon 2.747 8.75E-03 9.63E+06peek/kevlar 2.808 9.16E-03 1.01E+07
Composite Tensile STRGTH crack size a,mEpoxy/carbon 3.69E+08 1.34E-06Epoxy/kevlar 4.60E+08 1.01E-06Peek/carbon 3.59E+08 1.87E-05peek/kevlar 4.04E+08 1.54E-05
density kg/m^3 dollars/m^3epoxy 1260 Epoxy/carbon 52054carbon 1810 Epoxy/kevlar 16524kevlar 1440 Peek/carbon 160202.5peek 1310 peek/kevlar 124672.5
Volume fraction cost $/kg0.1 epoxy 60.9 carbon 2500.9 kevlar 67.50.1 peek 97.5
Peek is cheaper
-
Question8
Aerospace materials use 2xxx,6xxx,7xxx and 8xxx, which are all wrought. The only cast used is xxx or Axxx. The represents if the cast is pure or not.
Some examples of alloys 7075,6061,8090,2024,7475,7275,7375,7125 and A357. The difference between
7475 and 7075 is that 7475 is a customization of the former. It used for top-notch alloys that need very good fracture toughness. Also, 7475 is used in sheet and plate applications. 7075 is a good alloy that is used for important aerospace applications as well
