Effect of Cu addition on microstructural evolution and hardening of mechanically alloyed Al-Ti-O in-situ composite  

添加Cu对机械合金化Al-Ti-O原位复合材料显微组织演变和硬化的影响

作　　者：A.S.PROSVIRYAKOV A.I.BAZLOV I.S.LOGINOVA A.S.PROSVIRYAKOV;A.I.BAZLOV;I.S.LOGINOVA(Department of Physical Metallurgy of Non-Ferrous Metals,National University of Science and Technology“MISiS”,Leninskiy Prospect 4,Moscow 119049,Russia)

机构地区：[1]Department of Physical Metallurgy of Non-Ferrous Metals,National University of Science and Technology“MISiS”,Leninskiy Prospect 4,Moscow 119049,Russia

出　　处：《Transactions of Nonferrous Metals Society of China》2020年第5期1135-1147,共13页中国有色金属学报（英文版）

基　　金：the Ministry of Education and Science of the Russian Federation in the framework of the State Assignment to the Universities(Project No.11.7172.2017/8.9).

摘　　要：The microstructure formation and strengthening of an Al-5 wt.%TiO2 composites with additions of 5 wt.%Cu and 2 wt.% stearic acid(as a process control agent, PCA) during mechanical alloying and subsequent thermal exposure were studied. The powder composites were prepared by high-energy ball milling for up to 10 h. Single line tracks of the powders were laser melted. Optical and scanning electron microscopy, XRD analysis and differential scanning calorimetry were used to study microstructural evolution. The results showed that the Cu addition promotes an effective mechanical alloying of aluminum with Ti O2 from the start of milling, resulting in higher microhardness(up to HV 290), while the PCA, on the contrary, postpones this process. In both cases, the composite granules with uniform distribution of Ti O2 particles were formed. Subsequent heating of mechanically alloyed materials causes the activation of an exothermic reaction of Ti O2 reduction with aluminum, the start temperature of which, in the case of Cu addition,shifts to lower values, that is, the transformation begins in the solid state. Besides, the Cu-added material after laser melting demonstrates a more dispersed and uniform structure which positively affects its microhardness.研究添加5%Cu和2%(质量分数)硬脂酸(工艺控制剂,PCA)的Al-5%Ti O2(质量分数)复合材料在机械合金化和后续加热过程中显微组织的形成和强化。采用高能球磨法制备粉末复合材料,球磨时间长达10 h。用激光熔融对单线轨的粉末进行处理。利用光学和扫描电镜、X射线衍射分析技术和差示扫描量热法研究其显微组织演变。结果表明,Cu的加入能促进铝与Ti O2在球磨过程中的有效机械合金化,使粉末具有更高的显微硬度(高达HV 290);而PCA的效果恰恰相反。在这两种情况下,都形成了均匀分布的Ti O2复合颗粒。机械合金化材料的后续加热导致Ti O2与铝的放热反应,使得含Cu材料的开始反应温度变得更低,从固态开始发生转变。此外,激光熔融后含Cu材料具有更加分散和均匀的结构,有利于提高其显微硬度。

关 键 词：mechanical alloying Al-Ti-O system aluminum matrix composites MICROSTRUCTURE HARDENING laser melting 

分 类 号：TB33[一般工业技术—材料科学与工程]