Paper number 625

CHARACTERIZATION OF MECHANICAL AND IN-SITU FRACTURE BEHAVIORS OF REACTION SQUEEZE CAST HYBRID AL MATRIX COMPOSITES

Changook Son1, Ikmin Park1, Kyungmox Cho1, and Ildong Choi2

1Dept. of Metallurgical Engineering, Pusan National University, Pusan 609-735, Korea
2Dept. of Materials Engineering, Korea Maritime University, Pusan 606-791, Korea

Summary Mechanical properties of (10%Al2O3 SiO2+5%Ni)/Al and (10%Al2O3 SiO2+5%TiO2)/Al hybrid composites fabricated by the reaction squeeze casting were compared with those of (15%Al2O3 SiO2)/Al composites. Al-Ni and Al-Ti intermetallic compound formed by the reaction between molten aluminum and reinforcing powder were uniformly distributed in the Al matrix. These intermetallic compounds were identified as Al3Ni and Al3Ti using EDS and X-ray diffraction analysis and they enhanced room and high temperature strength. While tensile and yield strength of hybrid composites were greater at room temperature and 300oC than those of (15%Al2O3 SiO2)/Al composites, strength drop at high temperature was much smaller in hybrid composites. It was identified from the in-situ fracture test of (15%Al2O3 SiO2)/Al composites, microcracks were initiated mainly at the short fiber / matrix interfaces. As the loading was continued, the crack propagated mainly along the separated interfacial regions and the well developed shear bands. It was identified from the in-situ fracture test of (10%Al2O3 SiO2+5%Ni)/Al hybrid composites, microcracks were initiated mainly by the short fiber / matrix interfacial debonding. As the loading was continued, the crack proceeded mainly through the intermetallic compound clusters.
Keywords hybrid MMC, reaction squeeze casting, intermetallic compound, mechanical properties, in-situ fracture test.

Theme : Metal Matrix Composites

[ HOME ]  [ BACK ]