Low-temperature joining of boron carbide ceramics

Abstract

Low-temperature joining of boron carbide (B4C) ceramics using an Al sheet was investigated in the temperature range of 6001200° for 2 h in vacuum (10-210 -4 Pa). Successful joining and high bending strength close to that of the B4C base were achieved in the samples joined at 7001100°. Different techniques including scanning electron microscopy (SEM), electron probe microanalysis (EPMA) and transmission electron microscopy (TEM) were used to characterize the high-strength B4C joints. SEM observations suggested the dense interlayer and the crack-free interface as well as the penetration of Al into the surface microcracks of B4C base. Further TEM examinations revealed that B4C and Al joined directly. EPMA analysis demonstrated the existence of several reaction products within interlayer, including AlB2 and Al3BC, which resulted in the development of high-strength composite interlayer. © 2012 The Ceramic Society of Japan.