论文信息 - TiC/AZ91D composites fabricated by in situ reactive infiltration process and its tensile deformation

TiC/AZ91D composites fabricated by in situ reactive infiltration process and its tensile deformation

Abstract An innovative processing route was adopted to fabricate 42.1%(volume fraction) TiC/AZ91D magnesium matrix composites. The reinforcement TiC was in situ synthesized from elemental powders of Ti and C and the matrix magnesium alloy AZ91D pressurelessly infiltrated into the preform of Ti and C. A comparative tensile deformation tests were conducted on the as-synthesized TiC/AZ91D composites and magnesium alloy AZ91D. The true strain—stress curves were fitted by Hollomon relation and their failure mechanisms were finally analyzed. The results show that the in situ formed TiC can increase the tensile strength, and is especially effective at elevated temperatures. Theoretical calculation of the strain hardening exponent (n) for TiC./AZ91D composites indicates that the n value ranges from 0.71 to 0.82 when tensile deformation was carried out at 423-723 K and shows fracture with brittle characteristic. However, the n value of 0.11-0.32 obtained for the matrix alloy AZ91D shows typical ductile features at elevated temperatures.

[1] J. Gwyther,et al. Mechanical properties of engineering materials , 1970 .

[2] V. H. López,et al. Mg/TiC composites manufactured by pressureless melt infiltration , 2004 .

[3] Kon-Bae Lee,et al. Reaction products of Al–Mg/B4C composite fabricated by pressureless infiltration technique , 2001 .

[4] Jae-pyoung Ahn,et al. Characteristics of AA6061/BN composite fabricated by pressureless infiltration technique , 2001 .

[5] M. Kobashi,et al. Synthesis of TiC/Aluminum Composite by Reactive Infiltration Process , 2002 .

[6] N. Travitzky,et al. Microstructure and mechanical properties of Al2O3/Cu–O composites fabricated by pressureless infiltration technique , 1998 .

[7] M. Kobashi,et al. Synthesis of TiC Particle Reinforced Aluminum Composite by Reactive Infiltration Process , 2002 .

[8] Q. Jiang,et al. In situ synthesis of TiC from nanopowders in a molten magnesium alloy , 2003 .

[9] Huiyuan Wang,et al. In situ synthesis of TiC/Mg composites in molten magnesium , 2003 .

[10] J. Bi,et al. Synthesis of TiCp reinforced magnesium matrix composites by in situ reactive infiltration process , 2004 .

[11] Q. Dong,et al. Synthesis of TiC/Mg composites with interpenetrating networks by in situ reactive infiltration process , 2005 .

[12] Sie Chin Tjong,et al. Microstructural and mechanical characteristics of in situ metal matrix composites , 2000 .