金刚石厚膜表面金属化及其钎焊研究

Surface Metalization and Brazing of Diamond Thick Films

本文首先使用磁控溅射法在清洁的金刚石厚膜表面溅射Ti/Cu层,利用热的浓硫酸腐蚀表层的Cu和Ti层,获得具有合金TiC层的金刚石厚膜表面,实现金刚石厚膜的表面金属化;然后利用高频感应加热方法,以Ag-Cu-Ti混合粉末作为焊料进行金刚石厚膜的钎焊实验,主要对钎焊过程中的钎焊温度、保温时间以及焊料用量等参数进行了研究。结果表明,以60℃/s的速度加热到870℃后保温15 s,焊料用量为80μg时,金刚石厚膜与硬质合金刀具之间的焊接强度可以达到125 MPa,可以满足机械加工强度要求。

In this work,Ti/Cu layers were deposited on diamond thick films by magnetron sputtering.Then the surface Cu and Ti layers were corroded by hot concentrated sulfuric acid,while TiC layer remained on the surface.After this,the coated diamond thick film was brazed with hard alloy by high-frequency induction heating method,in which Ag-Cu-Ti mixed powder was used as the solder.The influences of brazing temperature,holding time and the amount of solder were studied in detail.Results show that when using 80 μg solder and increasing the brazing temperature to 870 ℃ by the speed of 60 ℃/s,then holding for 15 s,the weld strength of diamond thick film on hard alloy can reach 125 MPa,which is fit for machining.