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Vol.55, No.2, 98 ~ 110, 2017
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| Title |
| Effect of Added Gas-Atomized Al-Si/SiCp Composite Powder on the Sinterability and Mechanical Properties of Alumix 431 fabricated by Hot-Pressing Process |
| Eunsun Lee , Jeong-jung Oak , Yongjin Kim , Yongho Park |
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| Abstract |
| The aim of this study is to establish an optimized hot-press sintering condition for aluminum matrix composites (AMCs) by analyzing their sintered microstructure and mechanical properties. The fabricated AMCs in this study consisted of a blend of commercial Ecka Alumix 431 powder, and Al-Si/SiCp powder manufactured by gas atomizer (Al-Si/SiCp). The Al-Si/SiCp powder was added to the Alumix 431 powder as a binder. The blended powder was hot-pressed and sintered and its properties were analyzed based on three variables: the blending ratio of each powder, sintering time and sintering temperature. The MgZn2 phases in the Alumix 431 powder were finely and homogeneously distributed when the sintering temperature was increased. The liquid phase of the Al-Si alloy facilitated densification of the Alumix 431 particles and promoted a reduction in pores in the sintered body. Dispersion of the MgZn2 phases, degree of porosity and densification of the fabricated AMCs affected the ultimate tensile strength (UTS) of the sintered body at room temperature (RT). The highest UTS of the fabricated AMCs was 242MPa at RT. The optimum sintering conditions were: a mixing ratio of Al-Si/SiCp to Alumix 431 powders of 5 to 95 wt%, a sintering time of 30 min and a sintering temperature of 610 ℃. Wear behavior of the specimens prepared with the optimized sintering conditions included stick-slip, abrasive, adhesive and delamination phenomena for each test condition, under correlated vertical load and linear speed. †(Received April 25, 2016; Accepted August 16, 2016) |
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| Key Words |
| composites, sintering, mechanical properties, wear, scanning electron microscopy (SEM) |
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