窒化けい素セラミックとアルミニウム合金接合体の強度に及ぼす低温後熱処理とＭｇ添加の影響

Abstract

An aluminum alloy was joined to a silicon nitride ceramic with an Al-27.1Cu-4.7Si brazing filler metal at a brazing temperature of 813 K in a nitrogen gas atmosphere. A heat treatment at 723 K (post heat treatment at low-temperature) was performed after the joining. The joint strength was estimated from the shearing strength, and the effects of post brazing heat treatment at low-temperature and Mg content in the aluminum alloy on the joint strength were examined. Though the joint strength in the as-bonded state was very low, it increased to about 65 MPa after post brazing heat treatment at low-temperature for 7.2 ks. The post brazing heat treatment at low-temperature caused the decomposition of Al2Cu layer at the joining interface and the Cu diffusion into the aluminum alloy. Mg addition to the aluminum alloy increased the joint strength. The effects of Mg were the dissolution of an oxide scale on the aluminum surface and the enhancement of Cu diffusion into the aluminum alloy.