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金属学报    DOI: 10.11900/0412.1961.2024.00286
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TC4激光表面重熔层内拉伸变形{10-12}孪晶形成机制及马氏体变体选择规律研究
杨朋飞1,孙磊1,孙奇2,杨志远3,赵元1,高英1,张嘉振4

1 浙江师范大学 工学院  金华 321004

2 西南交通大学 材料科学与工程学院 材料先进技术教育部重点实验室  成都 610036

3 中材高新氮化物陶瓷有限公司  淄博 255000

4 中国商用飞机有限责任公司北京民用飞机技术研究中心  北京 102200

Study on the formation mechanism of{10-12}twins and the selection rule of martensitic variants in TC4 laser surface remelting layer

YANG Pengfei 1, SUN Lei 1, SUN Qi 2, YANG Zhiyuan 3, ZHAO Yuan 1, GAO Ying 1, ZHANG Jiazhen 4

1 College of Engineering, Zhejiang Normal University, Jinhua, 321004, China

2 Key Laboratory of Advanced Technologies of Materials (Ministry of Education), School of Material Science and Engineering, Southwest Jiaotong University, Chengdu, 610036, China

3 Sinoma Advanced Nitride Ceramics Co.,Ltd., Zibo, 255000, China

4 Beijing Aeronautical Science and Technology Research Institute of COMAC, Beijing, 102200, China

引用本文:

杨朋飞 孙磊 孙奇 杨志远 赵元 高英 张嘉振. TC4激光表面重熔层内拉伸变形{10-12}孪晶形成机制及马氏体变体选择规律研究[J]. 金属学报, 10.11900/0412.1961.2024.00286.

全文: PDF(6492 KB)  
摘要: 激光表面重熔技术(LSR)可有效提升TC4合金的力学性能,但是LSR过程对TC4试样显微组织和后续拉伸变形机制的影响尚不明确。本文在全马氏体TC4试样的正面和背面进行LSR处理,随后开展拉伸试验,利用透射电镜(TEM)和电子背散射衍射仪(EBSD)进行系统表征,深入探究材料在拉伸过程中的微观结构演变,特别是{10-12}" 孪晶的形成及其分布特征。结果表明:在LSR过程中,激光快速冷却特性显著诱发了残余应力,这一效应不仅促进了特定型马氏体变体的优先生成,还降低了孪晶开启所需的临界分切应力。同时,激光处理时Al元素的蒸发降低了材料的c/a比,减弱了晶格的各向异性,进一步促进了{10-12}孪晶的形成。这些孪晶主要集中于几种具有特定取向的马氏体变体中,这些变体在快速冷却条件下显示出明显的择优生成趋势。
关键词 TC4合金激光表面重熔异质结构{10-12}孪晶全马氏体    
Abstract:Laser surface remelting (LSR) technology can effectively improve the mechanical properties of TC4 alloy, but the effect of LSR process on the microstructure and subsequent tensile deformation mechanism is still unclear. In this paper, LSR treatment was applied on the front and back of full martensitic TC4 sample, and then tensile test was carried out. Systematic characterization was performed by transmission electron microscopy (TEM) and electron back scattering diffractometer (EBSD), to further explore the microstructure evolution during tensile process, particularly, the formation and distribution of {10-12} twins. The results show that the residual stress is induced significantly by rapid cooling during the LSR process, which not only promotes the preferential formation of specific martensite variants, but also reduces the critical shear stress required for twinning . Simultaneously, the evaporation of Al element during laser treatment reduces the c/a ratio of TC4 alloy, weakens the anisotropy of the crystal lattice, and further promotes the formation of {10-12}twins. These twins are mainly concentrated in several martensite variants with specific orientation, which shows an obvious tendency of preferential formation under the rapid cooling condition.
Key wordsTC4 alloy    Laser surface remelting    heterostructure    {10-12}twin    full martensite
收稿日期: 2024-08-19     
ZTFLH:  TG178  
基金资助:四川省自然科学基金项目;中央高校基本科研业务费专项
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