文章信息/Info

Title:

激光焊接Ti-6Al-4V鈦合金塑性行為的原位SEM/EBSD分析

作者:

DANG Ning1;  2;  LIU Lingyu3;  LAVOGIEZ Cyril2;  MAIRE Eric2;  MA Chaoli1;  ZHOU Lian1;  4

(1. School of Materials Science and Engineering,Beihang University, Beijing 100191, China)(2. INSA de Lyon, Mateis UMR 5510, Villeurbanne 69621, France)(3. Baoti Group Co��, Ltd��,Baoji 721014, China)(4. Northwest Institute for Nonferrous Metal Research, Xi�餫n 710016, China)

Author(s):

黨寧1; 2; 劉玲玉3; LAVOGIEZ Cyril2;  MAIRE Eric2; 馬朝利1; 周廉1; 4

(1. 北京航空航天大學材料科學與工程學院, 北京100191) (2. INSA de Lyon, Mateis UMR 5510, Villeurbanne 69621, France) (3.寶鈦集團有限公司，陜西 寶雞 721014)(4.西北有色金屬研究院，陜西 西安 710016)

關鍵詞:

crystallographic orientation;  in-situ SEM;  plastic deformation;  laser beam welding;  Ti-6Al-4V alloy

Keywords:

晶體學取向; 原位SEM; 塑性變形; 激光焊接; Ti-6Al-4V鈦合金

DOI:

10.7502/j.issn.1674-3962.2019.03.10

文獻標志碼:

A

摘要:

EBSD and in-situ SEM were used to study the plastic behavior of laser beam welding Ti-6Al-4V. Due to the high weld temperature(exceeding the β-transus) and high cooling rate, β→α′ martensitic transformation occurs. Within the fusion zone, only acicular morphology exists, while in 1st heat affected zone(HAZ) and 2ndHAZ, these acicular laths globalize, which show an obvious microstructural gradient. The result of the in�瞫itu plastic deformation shows the deformation can be divided into 2 stages. In the first stage of the deformation, either slipping or twinning can occur. It depends on whether the initial orientation can respect <120>//TA(tensile axis) by rotating the grains or not. While in the second stage, only slipping can be found.

Abstract:

選用原位SEM/EBSD顯微術分析研究了Ti-6Al-4V鈦合金的焊接區域的變形行為。研究發現，由于焊接時高的焊接溫度(在β相變點之上)和急劇的冷卻速率，導致β→α′ 馬氏體相變的發生。SEM觀察發現，在焊縫區只存在有針狀的α′馬氏體形貌，而在焊接第一熱影響區和第二熱影響區，針狀α′相逐漸發生球化，形成了明顯的顯微組織梯度過渡。在對焊接區域進行SEM/EBSD下的原位拉伸實驗后發現，該區域的塑性變形可劃分為兩個階段。變形的第一階段，滑移變形或孿生變形均有可能發生，這取決于晶粒的初始晶體學取向是否可通過旋轉來匹配<120>//TA(拉伸方向)；而在變形的第二階段，只發生滑移變形。