| Title |
Research Paper / Composite Materials : Fracture Mechanism of the Al-25Si-X Composite Fabricated via Spray Forming and Extrusion 1-Experimental Investigation |
| Authors |
석현광(Hyun Kwang Seok),박우진(Woo Jin Park),이호인(Ho In Lee),이재철(Jae Chul Lee) |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Abstract |
The fracture mechanisms operative in the hypereutectic Al-Si-X composites fabricated via spray forming and extrusion were investigated in an attempt to improve the mechanical properties of the composites. Two different types of Al-25Si-X composites were prepared by varying matrix composition and heat treatment conditions; the hard/brittle sample revealed 0.8% elongation with 420 ㎫ U.T.S and the soft/ductile one revealed 16% elongation with only 165 ㎫ U.T.S. The effect of the crystallographic factor of Si particles on the crack initiation in Al-25Si-X composite was regarded not to be important. In the case of the hard/brittle sample, the cracks were observed to be initiated from Si particles at a relatively high tensile stress of about 420 ㎫ followed by sudden crack propagation through the composite. On the other hand, in the soft/ductile sample, the stress was also concentrated at the Si particles. However, cracks were not developed until the sample was deformed in about 7-9% elongation. |