(中國工程物理研究院，綿陽 621900)
摘 要: 以AlSi合金為過渡材料，運用激光焊接技術(shù)實現(xiàn)Be與Be的連接；采用掃描電鏡、納米壓痕儀及透射電鏡對焊接接頭的顯微組織、剪切斷口形貌及性能進(jìn)行研究。結(jié)果表明：熔合區(qū)和焊縫區(qū)組織由Be與AlSi合金形成的復(fù)合相構(gòu)成，焊縫區(qū)顯微硬度和彈性模量分別為2 GPa和140 GPa，熔合區(qū)寬度約10 μm；焊接接頭剪切強度約為283 MPa，剪切斷口具有以準(zhǔn)解理為主并伴有塑性的混合型斷口特征，熔合區(qū)附近熱應(yīng)力誘發(fā)的微裂紋、焊縫中的金屬間化合物和氣孔是導(dǎo)致焊接接頭失效的主要原因。
關(guān)鍵字: 鈹；鋁硅合金；激光焊接；微觀組織
（China Academy of Engineering Physics, Mianyang 621900, China）
Abstract:Using AlSi alloy as transition material, beryllium with beryllium was welded by laser. The microstructure and performance of the welding joint were studied by means of nanoindentation apparatus, scanning electron microscope (SEM), electron probe microanalysis (EPMA) and transmission electron microscope (TEM). The results indicate that the microstructure of weld and fusion zone for the Be/AlSi/Be laser welding joint is composed of compound phase formed by beryllium and AlSi alloy, and the microhardness and elastic modulus of welding zone are 2 GPa and 140 GPa. The concentration distributions of Al and Si show that the width of fusion zone is about 10 μm. The shear strength of Be/AlSi/Be welding joint is 283 MPa. The characteristic of shear fractographs is quasi-cleavage with local ductile dimples. According to the analysis for shear fractographs, the micro-crack made by welding thermal stress, intermetallic compounds and gas porosities formed in welding zone are the main cause leading to brittle rupture for welding joint.
Key words: beryllium; AlSi alloy; laser welding; microstructure
