TiB_2颗粒对半固态铝基复合材料晶粒长大行为的影响  

Effect of In-situ Particles on the Grain Growth Behavior of Aluminum Matrix Composites at Semi-solid State

作　　者：张磊 杨滨[1,2] 陈薇娜[3] 张晓楠[3] 

机构地区：[1]航空材料热加工技术航空科技重点实验室,江西南昌330063 [2]北京科技大学新金属材料国家重点实验室,北京100083 [3]南昌航空大学材料科学与工程学院,江西南昌330063

出　　处：《铸造技术》2010年第8期991-994,共4页Foundry Technology

基　　金：中航一集团"材料热加工技术"航空科技重点实验室开放基金资助项目(ZK200801001);南昌航空大学"三小"科技创新基金项目

摘　　要：在脉冲磁场作用下,制备了含有不同原位TiB2含量铝基复合材料的半固态坯料,在600℃和620℃重熔并保温20 min,淬火固定半固态组织后,利用光学显微镜观察复合材料组织,应用晶相分析软件及平均截线法统计平均晶粒尺寸,分析不同颗粒含量对半固态铝基复合材料晶粒长大行为的影响规律。结果表明,原位TiB2颗粒不仅使复合材料的铸态组织转变为细小的等轴晶组织,而且在重熔过程中对晶粒长大行为具有抑制作用。当TiB2颗粒含量为6wt%时,表现出良好的钉扎效果,在600℃重熔仍保持细小等轴晶组织,完全满足后续半固态触变成形工艺要求。The grain growth behavior of the semi-solid billets of aluminum matrix composites prepared with XTiB2 （X = 0, 1.5 %, 3 %, 6 %） under pulsed magnetic field were studied. And the effects of in-situ TiB2 particles on the microstructure of composites were investigated. The specimens were heat treated at 600 ℃ and 620 ℃ for 20 min, then quenched in water and microstructures of reheated specimens were examined using optical microscope and the grain size was measured using a mean linear intercept method. It is shown that TiB2 particle not only can obviously refine and spheroidize the as-cast microstructure of semi-solid aluminum matrix composites, but also can significantly control the grain size during remelting. An evident pinning effete was achieved at 600℃ when TiB2 particle content was up to 6% ,which makes the alloy keep the refined equiaxed grains and meet the requirement of subsequent semi-solid processing.

关 键 词：半固态 原位TiB2颗粒 铝基复合材料 晶粒长大 

分 类 号：TB331[一般工业技术—材料科学与工程]