首页|退火处理对粉末冶金Ti2AlNb合金电子束焊接接头显微组织和拉伸性能的影响

退火处理对粉末冶金Ti2AlNb合金电子束焊接接头显微组织和拉伸性能的影响

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研究了焊态和退火处理态粉末冶金Ti2AlNb合金电子束焊接接头的显微组织与拉伸性能.结果表明,焊态下熔合区为单一 B2相,由粗大的柱状晶和等轴晶组成.经800~900 ℃焊后退火处理后,熔合区B2相内析出板条O相,形成O+B2相两相结构,随着退火温度升高,熔合区内O相尺寸增加,O相体积分数变化不大.焊接接头中熔合区显微硬度高于母材,焊后退火处理后,熔合区显微硬度升高,随着退火温度升高,熔合区显微硬度逐渐降低.焊态下,焊接接头表现出较高的室温拉伸强度和塑性,但在650 ℃高温拉伸时,焊接接头试样在未达屈服点时即在熔合区发生脆性断裂.经焊后退火处理,焊接接头室温拉伸强度和塑性略有降低,高温拉伸强度和塑性均显著改善,高温抗拉伸强度随退火温度升高而逐渐增加.
Influence of Annealing on Microstructure and Tensile Properties of Electron Beam Weldment of Powder Metallurgy Ti2AlNb Alloy
Annealing treatment in the temperature range of 800-900 ℃ was applied to the electron beam weldments of powder metallurgy Ti2AlNb alloys to investigate its influence on microstructure and tensile properties at room temperature and 650 ℃.The results show that there are coarse columnar and equiaxed B2 grains in the fusion zone(FZ)in the as-welded weldments.Transformation from B2 phase to O+B2 phase occurs in the FZ during the post-weld annealing treatments.The morphology of the O phase is characterized as the basket-weave structure and the size of the O phase plate increases with the increase in the annealing temperature.The microhardness of the FZ of the as-welded weldments is higher than that in the base metal(BM).After the annealing treatments,the microhardness in the FZ increases significantly,which gradually decreases with the increase in annealing temperature.At room temperature,all tensile specimens are fractured at the FZ.The tensile strength of the as-welded weldments is close to that of the BM and local large plastic deformation occurs in the FZ.However,the strength and ductility of the weldments decrease slightly after the post-weld annealing treatment.At 650 ℃,most of the tensile specimens are fractured at the FZ.The as-welded weldments are failured at the FZ,suggesting the brittle intergranular fracture.After the annealing treatments,there is an apparent improvement in strength of the FZ in the weldments.With the annealing temperature increasing up to 900 ℃,the failure locations are shifted from the FZ to the BM.

powder metallurgy Ti2AlNb alloyelectron beam weldmentannealing treatmentmicrostructuretensile property

尹续臣、陈志勇、王清江、刘建荣、李文辉、邓浩、罗恒军

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太原理工大学航空航天学院,山西太原 030024

中国第二重型机械集团德阳万航模锻有限责任公司,四川德阳 618000

中国科学院金属研究所,辽宁沈阳 110016

粉末冶金Ti2AlNb合金 电子束焊接接头 退火处理 显微组织 拉伸性能

山西省基础研究计划太原理工大学校基金

2021030212230522022QN152

2024

稀有金属材料与工程
中国有色金属学会,中国材料研究学会,西北有色金属研究院

稀有金属材料与工程

CSTPCD北大核心
影响因子:0.634
ISSN:1002-185X
年,卷(期):2024.53(8)