AlNP/Al复合材料与6061Al低温连接组织演变机理及力学性能

Microstructure evolution mechanism and mechanical properties of AlN_P/Al composites bonded to 6061Al at low temperature

为了防止在高温下连接电子器件发生破坏,并改善常用的低温SnAgCu钎料对母材25%(体积分数)AlNP/Al复合材料与6061Al合金表面的润湿性,对母材表面进行磁控溅射Ni薄层或Ti/Ni双金属薄层的预金属化处理,再用SnAgCu钎料进行连接,可得到结合良好的接头。双金属化后接头两侧界面组成为母材/Ti-Al/Ti/Ti-Ni/Ni/Ni-Sn-Cu/β-Sn+Ag3Sn。不同元素之间扩散速率的差异导致了界面反应层不同位置的物相成分差异,从镀Ni层向焊缝中心方向,反应层的物相呈(Ni,Cu)3Sn,(Ni,Cu)3Sn2,(Ni,Cu)6Sn5,(Ni,Cu)3Sn4的变化趋势。Ti元素的加入可显著提高镀Ni层与母材的结合力,在250℃下保温1-5 min,钎焊双金属化处理后的母材所得接头抗剪强度可达28-35 MPa,断裂发生在β-Sn基体中。

In order to prevent the damage of the connected electronic components at high temperature and improve the wettability of the commonly used low-temperature SnAgCu(SAC)solder on the surface of the base material 25%AlNP/Al(volume fraction)composite and 6061 Al alloy,the Ni thin layer or the Ti/Ni bimetal thin layer on the surface of the base metal were pre-metallized by magnetron sputtering,and then connected with a SnAgCu solder,a well-bonded joints was obtained.After double metallization,the interface on both sides of the joint is composed of base material/Ti-Al/Ti/Ti-Ni/Ni/Ni-Sn-Cu/β-Sn+Ag3Sn.The difference in diffusion speed between different elements leads to differences in the phase composition of the interface reaction layer at different positions.From the Ni plating layer to the center of the weld,the phase of the reaction layer is(Ni,Cu)3Sn,(Ni,Cu)3Sn2,(Ni,Cu)6Sn5,(Ni,Cu)3Sn4.The addition of Ti element can significantly improve the bonding strength between the Ni-plated layer and the base metal.The joint shear strength of the joint material obtained by brazing the base metal after double metallization at 250℃ for 1 min to 5 min can reach 28-35 MPa,fracture occurs at β-Sn matrix.