高能球磨及热挤压对Al-Ti-B细化剂纳米TiB_(2)颗粒分散性与细化性能的影响  

Effect of high-energy ball milling and hot extrusion on TiB_(2) nanoparticle dispersion and grain refinement property of Al-Ti-B refiner

作　　者：郭路 闫敬明 左孝青[1] 易健宏[1] 周芸[1] 苗琪 GUO Lu;YAN Jingming;ZUO Xiaoqing;YI Jianhong;ZHOU Yun;MIAO Qi(Faculty of Materials Science and Engineering,Kunming University of Science and Technology,Kunming 650093,China)

机构地区：[1]昆明理工大学材料科学与工程学院,昆明650093

出　　处：《材料科学与工艺》2023年第2期15-23,共9页Materials Science and Technology

基　　金：国家自然科学基金资助项目(51861020,51741103);云南省重点研发计划项目(2018BA072)。

摘　　要：为获得高晶粒细化性能的Al-Ti-B细化剂,本文利用高能球磨法在微米Ti粉上负载纳米TiB_(2)颗粒制备了Ti/TiB_(2)粉末细化剂,并采用热挤压工艺制备了杆状Al-Ti-B细化剂,对比分析了两种细化剂的晶粒细化性能及机理。研究表明:高能球磨可将纳米TiB_(2)颗粒均匀负载分散在微米Ti粉表面,使工业纯铝的平均晶粒尺寸细化至74.6μm;热挤压则使细化剂致密化,微米Ti粉及纳米TiB_(2)颗粒在铝基体中分布更加均匀,可将工业纯铝的平均晶粒尺寸进一步细化至58.4μm,获得最佳细化效果,并使细化剂的抗衰退性能提高。机理分析表明,随着细化剂中纳米TiB_(2)颗粒的分散性提高、团聚现象减缓,其在铝熔体中的沉降速度缓慢,对晶粒的形核促进作用、长大抑制作用更充分,是热挤压Al-Ti-B细化剂对工业纯铝有优异晶粒细化效果的关键。To obtain Al-Ti-B refiner with good grain refinement property,Ti/TiB_(2) powder refiner was prepared by loading TiB_(2) nanoparticles(NPs)on micron Ti powder via high-energy ball milling(HEBM),and rod-like Al-Ti-B refiner was prepared by hot extrusion.The grain refinement properties and mechanisms of the two refiners were compared and analyzed.Results show that TiB_(2) NPs were evenly dispersed on the micron Ti powder by HEBM,and the average grain size(AGS)of commercial pure aluminum(CPA1)was 74.6|im after refinement.Through hot extrusion,the refiner was densified,and micron Ti powder and TiB_(2) NPs were more evenly distributed in Al matrix;AGS of CPA1 was further refined to a best level of 58.4|xm,and the anti-fading performance of the refiner was improved.The mechanism analysis shows that the settling velocity of dispersed TiB_(2) NPs in aluminum melt was slowed down with improving dispersibility of TiB_(2) and decreasing agglomeration,causing more sufficient effects on promotion of grain nucleation and inhibition of grain growth,which is the key to the excellent CPA1 grain refining effect of hot extruded Al-Ti-B refiner.

关 键 词：Al-Ti-B细化剂 高能球磨 热挤压 纳米TiB_(2)颗粒分散性 晶粒细化 

分 类 号：TG146[一般工业技术—材料科学与工程]