TA15合金热挤压过程中晶界特征分布研究  

Grain boundary characteristic distribution during hot extrusion for TA15 alloy

作　　者：刘勇[1] 朱景川[1] 王洋[1] 

机构地区：[1]哈尔滨工业大学材料科学与工程学院,黑龙江哈尔滨150001

出　　处：《材料热处理学报》2009年第2期39-43,共5页Transactions of Materials and Heat Treatment

摘　　要：采用EBSD方法研究了TA15合金热挤压成形过程中的晶界特征分布演化规律。TA15合金分别在850、925和960℃温度下进行单筋正向热挤压变形,变形速率分别采用0.3mm/s和0.1mm/s,压下量分别取80%、60%、40%。研究表明,原始组织α相特殊晶界比例为12.04%,变形后特殊晶界比原始状态均有所减小。在变形温度为925℃,特殊晶界比例最小,960℃变形后特殊晶界比例有所升高;850℃和960℃变形后特殊晶界以∑5,∑17a和∑27a为主,而925℃变形后特殊晶界类型分布比较分散。随变形量的增加,特殊晶界数量先减小,后又增加,到变形量为60%时达到极大值;变形量40%和60%产生的特殊晶界以∑5,∑17a和∑27a类型为主,当变形量达到80%时,特殊晶界类型变得极为分散。随应变速率的增加,特殊晶界的比重减小,而小角晶界的比重增加。The variation of grain boundaries character distributions of TA15 alloy during hot extrusion were investigated. The specimens were hot extruded at 850,925 and 960 ℃, at 0.3mm/s and 0.1 mm/s with strain of 80 %, 60 % and 40 %, respectively. The results show that special grain boundary ratio decreases in deformed specimen than that of starting microstructure with the value of 12.04%. The special grain boundary amount shows a minimum value for deformation at 925℃, and an increase when increasing deformation temperature to 960℃, The predominated types of special grain boundary include ∑5, ∑ 17a and ∑ 27a type at deformation temperature of 850℃ and 960℃, and increasing deformation temperature to 960℃ results in an relatively random distribution in special grain boundary. The special grain boundary shows an decrease when deformation amount increases firstly, then increase up to a maximum value at the 60 % deformation amount; The predominated types of special grain boundary include ∑5, ∑17a and ∑27a type at deformation amount of 40% and 60% , and 80% deformation amount yields a relatively random distribution in special grain boundary. An increase of strain rate results in an decrease of special grain boundary and large angle grain boundary, while an increase of small angle boundary.

关 键 词：TA15合金 晶界特征分布 

分 类 号：TG146.2[一般工业技术—材料科学与工程]