(哈爾濱工業(yè)大學(xué)材料科學(xué)與工程學(xué)院，哈爾濱 150001)
摘 要: 研究了擠壓比和擠壓溫度對(duì)擠壓鑄造SiCw/L3復(fù)合材料組織和性能的影響。結(jié)果表明，當(dāng)擠壓溫度升高時(shí)，晶須沿?cái)D壓方向定向排列程度基本未變，而晶須的折斷程度則減弱，導(dǎo)致復(fù)合材料的抗拉強(qiáng)度提高；當(dāng)擠壓比增大時(shí)，晶須沿?cái)D壓方向定向排列程度增大，晶須的折斷程度也增大，這兩個(gè)決定強(qiáng)度的相反過程造成了復(fù)合材料的抗拉強(qiáng)度在擠壓比為18∶1時(shí)出現(xiàn)最大值。用修正的混合法則預(yù)測(cè)擠壓態(tài)復(fù)合材料強(qiáng)度時(shí)，必須增大基體對(duì)強(qiáng)度貢獻(xiàn)部分的系數(shù)c*。
關(guān)鍵字: SiCw/Al復(fù)合材料 熱擠壓 組織 抗拉強(qiáng)度
（School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, P R China）
Abstract:Effects of extrusion ratio and temperature on the microstructure and properties of 15%SiCw/L3 composites have been investigated. Results showed that , with an increase of extrusion temperature the degree of whiskers' directional alignment along the extrusion direction nearly remains unchanged, but the breakage degree of whiskers decreases, which results in an increase of tensile strength. And with an increase of extrusion ratio the degree of whiskers' directional alignment along the extrusion direction increases and the breakage degree of whiskers increases too, which together result in a maximum value of tensile strength at an extrusion ratio of 18∶1. The coefficient c* representing the contribution of matrix to the strength, ought to be increased when the modified Rule of Mixture (ROM) is used to predict the strength of extruded composites.
Key words: SiCw/Al composite; hot extrusion; tensile strength
