纤维体积分数的改变对Al_2O_(3f)/Al-9Cu凝固组织的影响  

Influence of Different Volume Fraction of Fiber on Solidification Microstructure in Al_2O_(3f)/ Al-9Cu Composites

作　　者：靖青秀[1] 朱应禄[1] 

机构地区：[1]江西理工大学材料与化学工程学院,江西赣州341000

出　　处：《稀有金属》2006年第1期43-46,共4页Chinese Journal of Rare Metals

基　　金：教育部科学技术研究重点项目(00191);江西省自然科学基金项目(0150032)资助

摘　　要：挤压铸造制备了含不同纤维体积分数Vf的Al2O3f/Al-9Cu复合材料,研究分析了Vf的改变对复合材料凝固组织的影响。结果表明:复合材料在压铸并保压一段时间的条件下凝固,基体铸造性能提高;随着Vf的增大,复合材料基体晶粒细化,当纤维间隙尺寸大于同样条件下凝固的未增强基体合金的二次枝晶间距λ时,基体的结晶受纤维的影响很小,生成的晶粒粗大;当λf<λ时,纤维对基体的凝固干扰加大,基体晶粒尺寸将减小至纤维间隙大小;随着Vf的增大,复合材料凝固后基体中共晶组织的生成量fe还将有轻微的减少,组织偏析有所减轻;Vf对fe的影响关系可由Clyne-Kurz公式计算近似得出。Al2O3f/Al-9Cu composites with different volume fraction of fiber （Vf） were manufactured by squeeze casting and observed on SEM to explore the influence of Vf on solidification microstructure in composites. The results indicate that the matrix grain is fined and the casting properties of the matrix are improved by pressure casting. As Vf increases, the matrix grains are to be finer. If λ f 〉 λ, fibers almost do not influence the solidification behavior of the matrix so much, so the final grains become more coarse, where is the average interfiber spacing and ,λ the secondary dendrite ann spacing which would develop in the unreinforced alloy; But if λf 〈 λ , the growth of the matrix crystal is disturbed significantly by fibers, and the grain size is reduced to the value of the interfiber spacing. The amount of eutectic is reduced as Vf increases. The formula of Clyne-Kurz can be used to approximately calculate their functional relationship.

关 键 词：短纤维 铝铜合金 复合材料 挤压铸造 

分 类 号：TB331[一般工业技术—材料科学与工程] TG249.2[金属学及工艺—铸造]