(1. 河海大學(xué) 力學(xué)與材料學(xué)院，南京 210098；
2. 河海大學(xué) 宿遷研究院, 宿遷 223800)
摘 要: 采用等通道轉(zhuǎn)角擠壓工藝(ECAP)對(duì)兩種鑄造鋁硅合金(ZL101和ZL102)進(jìn)行不同道次的加工，研究晶粒細(xì)化及硅形態(tài)對(duì)合金力學(xué)性能的影響。結(jié)果表明：多道次ECAP能有效細(xì)化針狀共晶硅相并改善其在鋁基體中分布的均勻性，具有尺寸細(xì)小、分布彌散且棱角鈍化共晶硅的鋁硅合金具有更優(yōu)的力學(xué)性能；鑄態(tài)合金ECAP加工后強(qiáng)度和韌性均獲提高，固溶+16道次ECAP加工后ZL102合金的伸長(zhǎng)率和抗拉強(qiáng)度約為鑄態(tài)的5.04倍和1.39倍；隨擠壓道次的增加，兩種合金的斷裂方式均由脆性斷裂向韌性斷裂轉(zhuǎn)變；固溶后擠壓可獲得優(yōu)良的強(qiáng)韌組合，滿足制造行業(yè)需要。
關(guān)鍵字: 鋁硅合金；等通道轉(zhuǎn)角擠壓；晶粒細(xì)化；共晶硅；力學(xué)性能
（1. School of Mechanics and Materials, Hohai University, Nanjing 210098, China;
2. Suqian Institute, Hohai University, Suqian 223800, China）
Abstract:Two casting Al-Si alloys(ZL101 and ZL102) were processed by multi-pass equal-channel angular pressing (ECAP) for grain refinement, and the effects of morphology change of Si particles on their mechanical behaviors were studied. The results show that ECAP could effectively reduce the size of needle-like eutectic silicon and homogeneously disperse it in the Al matrix. The alloy with small and obtuse silicon particles dispersed in the Al matrix has better mechanical behaviors. ECAP can simultaneously improve the strength and plasticity of the as-cast alloys. The elongation and the tensile strength of the ZL102 alloy after solution-treatment plus 16 ECAP passes are 5.04 and 1.39 times as much as those of the as-cast sample, respectively. With the increase of the pressing pass, the fracture mechanism of two alloys changes from brittle fracture to ductile fracture. The combination of solution treatment and ECAP can obtain excellent strength and plasticity of the Al-Si alloys, which can meet the needs of manufacturing industry.
Key words: Al-Si alloy; equal-channel angular pressing; grain refinement; eutectic silicon; mechanical behavior
