难变形高温合金GH4720Li的超塑性变形行为  

Superplastic behavior of hard-to-deformed GH4720Li superalloy

作　　者：于秋颖[1,2] 姚志浩[2] 董建新[2] 张盼达 韩刚[2] 

机构地区：[1]中国航空工业集团公司北京航空材料研究院,北京100095 [2]北京科技大学材料科学与工程学院,北京100083

出　　处：《材料热处理学报》2015年第7期30-35,共6页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金(51404222);航空科学基金(2014ZF21029);高等学校博士学科点专项科研基金(20130006120005)

摘　　要：利用等温热压缩模拟试验机,对难变形高温合金GH4720Li初始均匀细晶合金不同温度及应变速率下的变形行为研究,计算了判定合金超塑性变形范围的应变速率敏感因子m及对相应变形组织进行分析。结果表明,均匀细晶合金在1040-1130℃、0.0001-0.005 s^-1变形区间内,m值随变形温度升高和变形量增加而降低;1040-1100℃、0.0001-0.005 s^-1条件下,该细晶合金具有超塑变形的能力,而1130℃时,无论应变速率如何,该合金已经不具备超塑性变形的能力;均匀细晶合金在较高变形温度下最佳超塑性变形所对应的应变速率较高,低温变形时最佳超塑性变形发生需要更低的应变速率。Superplastic behavior of initial uniform fine-grain GH4720 Li superalloy at different temperatures and strain rates was studied using isothermal compressive deformation simulation testing machine. Strain rate sensitivity factor m determining the domain of superplasticity was calculated and the corresponding microstructure evolution was analyzed. The results shows m value decreases with the increasing of temperature and strain in the range of 1040-1130 ℃,0. 0001-0. 005 s^- 1. The superplasticity of uniform fine-grain GH4720 Li superalloy is exhibited under the conditions of 1040-1100 ℃,0. 0001-0. 005 s^- 1. However,no superplasticity at 1130 ℃ is found.Optimal superplasticity at higher temperatures is obtained at relatively higher strain rates,and optimal superplasticity at lower temperatures can occur at lower strain rates.

关 键 词：难变形高温合金GH4720Li 热变形 超塑性 应变速率敏感因子 

分 类 号：TG132.3[一般工业技术—材料科学与工程]