Titanium Diboride Reinforced Boron Carbide · Titanium Diboride Reinforced Boron Carbide Azmi M....
Transcript of Titanium Diboride Reinforced Boron Carbide · Titanium Diboride Reinforced Boron Carbide Azmi M....
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Titanium Diboride Reinforced Boron Carbide
Azmi M. Celik, Dr. Chawon Hwang, Dr. Vladislav Domnich, Dr. Atta Ullah Khan, Dr. Richard A. Haber Rutgers, The State University of New Jersey
How We Fit Major Results Major Results (Continued)
Key Goals
Impact
Materials-by-Design Process
Transitions to ARL, within CMRG and to other CMRGs
Mechanism-based Approach
UNCLASSIFIED
UNCLASSIFIED
Technical Approach
Microstructure Evaluation & Vickers Hardness (HP) Crack Propagation Behavior (SPS)
• Improve mechanical properties and investigate toughening mechanisms of boron carbide-titanium diboride composites
• Fabricate industry-scale samples via Hot Press
crackbranching
transgranularintergranular
B4CTiB2
B4CB4C+TiB2
Key Accomplishments
To improve its resistance to crack propagation, boron
carbide (B4C) was reinforced with titanium diboride (TiB2).
Spark plasma sintering was utilized in preliminary work to
investigate microstructure and crack propagation behavior.
The most promising composition (B4C + 10wt%TiB2) was
hot pressed to examine feasibility of large-scale production.
• Optimize sintering conditions to achieve full densification
via Spark plasma sintering (SPS) and Hot press (HP)
• Identify the mechanisms of improvement in hardness
and toughness of B4C by TiB2 incorporation
HotPressedB4C-10wt%TiB2(ø4”)
Hot Pressing Conditions: 2150ºC, 4.5 hr, 24 MPa ρ = 2.64 g/cm3 (>99.9%)
B4C
Grain size: ~10-20 µm
B4C+10wt% TiB2
TiB2B4C
B4C Grain size: ~1-2 µm
• Composites with improved toughness were produced
• Hot press was utilized to fabricate large samples (up to ø6”)
• Grain growth in B4C was suppressed by TiB2 addition (HP)
TiB2 addition inhibits the grain growth of B4C
Sample Hv(1kg), GPa Std. dev. KIc, MPa.m1/2 Std. dev. Monolithic B4C 30.03 1.50 2.30 0.19 B4C + 10wt%TiB2 32.92 1.47 2.77 0.51
Spark Plasma Sintering Conditions: 1950ºC, 5 minutes, 50 MPa
• Ballistic impact tests on hot pressed plates to investigate
ballistic performance (ARL)
• Kolsky bar expt. to examine fracture and fragmentation (JHU)
• Fundamental research can help understanding and engineering
new composite microstructures to achieve improved material
properties such as hardness, toughness, and Young’s modulus
• Materials with engineered microstructures can be fabricated in
large-scale via hot press for possible ballistic applications
Hv
(GP
a)
Load (kg)