(中南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410083)
摘 要: 采用噴射沉積和熱擠壓致密化相結(jié)合的方法制備Al-27%Si合金，研究熱處理對合金的組織及性能的影響。利用金相顯微鏡、掃描電鏡和MTS-858型疲勞試驗機等手段對Al-27%Si合金噴射沉積擠壓態(tài)和熱處理態(tài)的顯微組織和力學(xué)性能進行觀察與測試。結(jié)果表明：噴射沉積Al-27%Si合金組織細小均勻，初晶Si均勻彌散地分布在連續(xù)Al基體中，無針狀共晶硅存在；采用合理的熱擠壓致密化工藝可以顯著消除材料中的孔隙，致密度達到99.5%；熱處理能夠進一步改善材料的組織，但會降低材料的屈服強度。
關(guān)鍵字: 噴射沉積；Al-27%Si合金；熱擠壓；熱處理；組織；屈服強度
（School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:A kind of novel packaging material, Al-27% alloy, was prepared by a method comprised of spray deposition and subsequent hot extrusion, then, the effects of heat treatments on the microstructures and mechanical properties of the alloy were studied. The microstructures and mechanical properties of hot extruded and heat treated Al-27%Si alloy were investigated with optical microscope, scanning electronic microscope and MTS-858 type fatigue testing machine. The experimental results show that the spray-deposited Al-27%Si alloy after hot extrusion has fine, homogeneous microstructure with no needle-like eutectic Si but small primary Si particles uniformly dispersed in the Al matrix, besides an increase of size to some degree, even the following heat treatments make little difference to it. Appropriate hot extrusion process can eliminate the porosities remarkably, so as to improve the relative density of the alloy to 99.5%. The microstructures of Al-27%Si experience further improvement after certain heat treatments, while the transformations of mechanical properties are opposite.
Key words: spray deposition; Al-27%Si alloy; hot extrusion; heat treatments; microstructures; yield strength
