强流脉冲电子束诱发的微观晶体缺陷及其对Cu-316 L不锈钢扩散连接性能的影响

Microscopic Crystal Defects Induced by Intense Pulsed Electron Beams and their Effects on the Diffusion Bonding Performance of Cu-316 L Stainless Steel

文章利用强流脉冲电子束(HCPEB)在Cu和316 L不锈钢表面进行电子辐照预处理,随后将二者进行真空扩散焊接处理。焊接温度为800℃和850℃、焊接压力为5 MPa、焊接时间为40 min。通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)等仪器观察了HCPEB辐照后316 L不锈钢的微观结构变化。微观结构观察表明,HCPEB辐照后,316 L不锈钢的初始粗晶粒明显转变为具有大量晶体缺陷的细晶粒。对未经辐照的Cu和316 L进行扩散焊接发现,制备的原始接头的焊接区域没有完全焊合。相比之下,经过HCPEB预处理的样品在扩散焊接后则显示出良好的焊合界面,同时Cu在界面处的扩散系数也显著增加。扩散系数的增加归因于辐照诱发的大量晶体缺陷为原子扩散提供了快速扩散通道,使得原子的扩散能力增强。结合强度结果表明,经HCPEB预处理后进行扩散焊接的Cu-316 L接头的剪切强度远高于原始接头。

This article uses a high current pulsed electron beam(HCPEB)for electron irradiation pretreatment on the surface of Cu and 316 L stainless steel,followed by vacuum diffusion welding treatment of the two.The welding temperature is 800℃ and 850℃,the welding pressure is 5 MPa,and the welding time is 40 minutes.The microstructure changes of 316 L stainless steel after HCPEB irradiation were observed using scanning electron microscopy(SEM),transmission electron microscopy(TEM),and other instruments.Microscopic observation shows that after HCPEB irradiation,the initial coarse grains of 316 L stainless steel significantly transform into fine grains with a large number of crystal defects.Diffusion welding of non-irradiated Cu and 316 L revealed that the welding area of the prepared original joint was not fully welded.In contrast,the samples pretreated with HCPEB showed a good bonding interface after diffusion welding,and the diffusion coefficient of Cu at the interface also significantly increased.The increase in diffusion coefficient is attributed to the large number of crystal defects induced by irradiation,which provides a fast diffusion channel for atomic diffusion and enhances the diffusion ability of atoms.The bonding strength results indicate that the shear strength of the Cu-316 L joint pretreated with HCPEB for diffusion welding is much higher than that of the original joint.