Al含量对MA-SPS制备Ti-Al合金组织与电阻率的影响  

Effects of Al Content on Microstructure and Resistivity of Ti-Al Alloys Prepared by MA-SPS

作　　者：徐灿 陈哲[1] 程婧璠[1] 蔡启舟[1] Xu Can;Chen Zhe;Chen Jingfan;Cai Qizhou(State Key Laboratory of Materials Processing and Die&Mould Technology,Huazhong University of Science and Technology)

机构地区：[1]华中科技大学材料成形与模具技术国家重点实验室,武汉430074

出　　处：《特种铸造及有色合金》2022年第2期184-189,共6页Special Casting & Nonferrous Alloys

基　　金：武汉市2019年度第一批创建国家科技创新平台项目。

摘　　要：采用机械合金化-放电等离子烧结(MA-SPS)技术制备了不同Al含量的Ti-Al合金,研究了Al含量对Ti-Al复合粉末形貌、Ti-Al合金组织与电阻率的影响。结果表明,高能球磨过程中Ti/Al复合粉末扁平化,Al固溶于Ti中,当Al含量高于9%后,部分Al固溶于Ti,而未固溶的Al破碎为细小颗粒附着于Ti颗粒表面,颗粒表面粗糙度增加,颗粒截面呈层状结构。当Al含量为6%时,球磨粉末烧结试样组织为单相α-Ti(Al)固溶体,Al含量为9%~12%,组织为α-Ti(Al)相及其晶界析出的细小α_(2)颗粒。当Al含量超过12%后,组织为α-Ti(Al)固溶体和α_(2)-Ti_(3)Al双相组织。合金电阻率随着Al含量的增加先增大后减小,Al含量为18%时,又略有增加。Al含量为9%时,电阻率达最大值2.074μΩ·m。Ti-Al alloys with different Al contents were fabricated by mechanical alloying and spark plasma sintering(MA-SPS). The effects of Al content on the composite powder morphologies, microstructure and electrical resistivity of SPS Ti-Al alloys were investigated. The results indicate that Ti-Al composite powders are flattened during high energy ball milling with Al dissolved into Ti. When the content of Al is higher than 9%, part of Al is dissolved into Ti, while the insoluble Al is broken into fine particles and attached to the surface of Ti particles, resulting in the increase of surface roughness, where the cross section of particles presents a layered structure. When the amount of Al is 6%, the microstructure of SPS specimen prepared by ball milled powders is single-phase α-Ti(Al) solid solution, which becomes α-Ti(Al) phase and fine α_(2)particles precipitated in grain boundary when the amount of Al is 9%~12%. When the amount of Al exceeds 12%, the microstructure is dual-phase composed of α-Ti(Al) and α_(2)-Ti_(3)Al. The electrical resistivity of the alloys is firstly increased and then decreased with the increase of Al content, and slightly increased when the amount of Al reaches 18%.The electrical resistivity reaches the maximum value of 2.074 μΩ·m when the Al content is 9%.

关 键 词：TI-AL合金 机械合金化 放电等离子烧结 微观组织 电阻率 

分 类 号：TG146.2[一般工业技术—材料科学与工程]