Research on the Microstructure and Properties of Mild Steel/High Chromium Iron Bimetal Materials

Author of the article:WANG Sha1 , WANG Tiejun1 , LI Chuanbo1 , SONG Dazhuo2 , SHI Lin2 , SUN Lixing2

Author's Workplace：1. BYD Fodi Technology Brake Factory, Xi'an 710100, China; 2. School of Materials Science and Engineering, Xi'an University of Technology, Xi'an 710048, China

Key Words：diffusion bonding; mild steel; high-chromium iron; microstructure; strength

Abstract：In this work, high chromium iron/mild steel bimetallic materials with different bonding temperatures were prepared using the method of vacuum melt infiltration diffusion bonding. The microstructure of the bimetallic materials was observed. Simultaneously, the interface shear strength and microhardness of the bimetallic materials were tested. The results show that the microstructures of the interface of the bimetallic materials aresignificantly different at 1 010 ℃, 1 030 ℃ and 1 050 ℃. The interface shear strength of the bimetallic materials is 320 MPa at 1 030 ℃, 298 MPa at 1 010 ℃ and 318 MPa at 1 050 ℃. The thickness of the CuCr interlayer reaches 90 μm at 1 010 ℃, indicating that the diffusion rate of elements is slow at low temperature. At 1 050 ℃, the CuCr interlayer softens obviously, and the diffusion layer is narrow with intermetallic compounds and microscopic pores, which reduces the interface shear strength of bimetallic materials.