Al-SiクラッドAlインサート材によるセラミックスと金属の接合

Abstract

Bonding of non-oxide ceramics (pressureless sintered silicon nitride, silicon carbide and sialon) to metals with interlayers of aluminium clad with aluminium-silicon alloy was performed at high temperatures and at pressures in vacuum of 2-4×10−2 Pa. Bonding conditions, bending strengths and thermal stresses generated due to the difference in thermal expansion between ceramic and metal were studied. Bending strengths of the specimens were measured by means of four point bending.Silicon nitride, silicon carbide and sialon were able to be bonded to metals by means of the interlayer of aluminium sheet clad with Al-10%Si alloy on both sides. High bending strengths were obtained in the specimens bonded in the temperature range between the melting point of the aluminium core and that of the Al-10%Si clad metal.The bending strength was found to be influenced by the thermal expansion mismatch, thus it decreased with increasing difference in thermal expansion coefficient between ceramic and metal. Further, it is considered that other factors such as the parent strength, fracture toughness, the Young’s modulus of ceramic and the reaction products at the bonded interface also exert an influence on the bending strength.Increase in thickness of the aluminium core of the interlayer was effective in the improvement of the bending strength. This improvement was explained by considering the relief of the thermal stress due to the softness of aluminium.According to high temperature bend test, the bending strengths up to 573 K were as high as that at room temperature.