(1. 武漢理工大學(xué) 現(xiàn)代汽車零部件技術(shù)湖北省重點(diǎn)實(shí)驗(yàn)室，武漢 430070；
2. 湖南大學(xué) 汽車車身先進(jìn)設(shè)計(jì)制造國家重點(diǎn)實(shí)驗(yàn)室，長沙 410082；
3. 武漢理工大學(xué) 汽車工程學(xué)院，武漢 430070；
4. 武漢理工大學(xué) 材料科學(xué)與工程學(xué)院，武漢 430070)
摘 要: 本文采用預(yù)成形-高速?zèng)_擊點(diǎn)焊工藝，獲得到了連接強(qiáng)度較好的DP590/Al3003異種材料點(diǎn)焊接頭。通過光滑粒子動(dòng)力學(xué)模擬方法(SPH)分析了接頭連接界面形成規(guī)律，并實(shí)驗(yàn)研究了接頭界面特征與形成機(jī)理。結(jié)果表明：接頭界面具有波形特征，連接強(qiáng)度與波形界面的波形參數(shù)存在一定關(guān)系；預(yù)成形直徑較小或放電能量較低時(shí)外側(cè)區(qū)域界面波形不明顯；隨預(yù)成形直徑增加，外側(cè)區(qū)域出現(xiàn)界面波且波長波幅呈增加趨勢(shì)；一定范圍內(nèi)，隨放電能量增加，即飛板速度增加時(shí)，連接界面中間區(qū)域的界面波的波長逐漸減小而波幅增加，外側(cè)區(qū)域界面波波長和波幅均增大，連接強(qiáng)度增加；SEM和EDS分析結(jié)果表明，連接界面產(chǎn)生了裂紋和旋渦組織，并生成了少量金屬間化合物。
關(guān)鍵字: 沖擊成形；異種金屬；點(diǎn)焊；界面波形
（1. Hubei Key Laboratory of Advanced Technology for Automotive Components, Wuhan University of Technology, Wuhan 430070, China;
2. State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Changsha 410082, China;
3. School of Automotive Engineering, Wuhan University of Technology, Wuhan 430070, China;
4. School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China）
Abstract:The preform-high rate impact spot welding process was proposed to join the aluminum and steel in this paper, and DP590/Al3003 joints with satisfied joining strength were obtained. The joint interface formation rule was investigated with smooth particle hydrodynamics (SPH) analytical method, and the interface characters and formation mechanism were experimental analyzed. The results show that, the joint interface shows the wave characters and the joint tensile resistance is related to the interface wave parameters. Few wave shows in the outside zone of interface when the preform diameter or discharging energy is small. With the preform area enlarges, the wavelength and amplitude increase in the outside zone. With the increase of discharging energy in a range, meanwhile with the increase of impact rate of flyer sheet, the wavelength decreases and amplitude increases in the middle zone of interface, but both increase in outside zone, and the tensile resistance enhances. The SEM and EDS results show that micro-crack and vortex microstructures appear inside the interface and interlayer metal compounds generate.
Key words: impact forming; dissimilar metals; spot welding; interface waveform
