摘要
研究了时效时间对激光快速成形后时效硬化镍基高温合金Rene′88DT中沉淀相组织演化和力学性能的影响。发现随时效时间的增加,沉淀相γ′略有长大,颗粒之间发生大颗粒吞噬小颗粒的粗化,时效40h后沉淀相颗粒粗化明显。对经不同时间时效后的激光快速成形Rene′88DT试样进行了硬度测试。结果显示,在时效时间为28h时,硬度有一峰值HRC49。在此基础上,采用1165℃,2h固溶、空冷+760℃,28h时效的热处理工艺对激光快速成形标准拉伸棒样进行了热处理,拉伸结果显示成形件的抗拉强度较激光沉积态提高了400MPa,屈服强度接近同种材料的粉末锻造水平。
Abstract： The γ′ precipitation evolution at different aging time and the mechanical properties of laser rapid forming （LRF） processing of Rene′88DT superalloy were investigated. It was found that the tiny γ′ precipitation grew a little with the increase of aging time, but precipitation coarsening took place because of mutual swallowing among precipitates. Especially after 40 h aging treatment, precipitation coarsening was obvious. The hardness testing of LRF Rene′88DT after different aging time was done. The result showed that there was a peak value of HRC 49 after 28 h aging treatment. Based on the results the process of 1165 ℃, 2 h air cooling solution treatment＋760 ℃, 16 h and 28 h aging treatment was selected to heat treat the LRF Rene′88DT tensile bars. The results showed the tensile strength after the process increased by 400 MPa, compared to as-deposition strength. The yield strength was even equal to that of the powder forging standard.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2007年第12期2208-2211,共4页
Rare Metal Materials and Engineering
基金
国家自然科学基金重点项目(No.50331010)
