Affiliation:
1. School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
Abstract
The Al-Nb/Ti/Ni composite was fabricated from pure Al, Ni, Ti, and Nb sheets by the ARB technology. The microstructure evolution was observed by scanning electron microscopy, x-ray diffraction, and transmission electron microscopy. The evolution was evaluated by the electron backscattered diffraction (EBSD) technique. A couple of results we obtained showed that the microstructure of Al changed from equiaxed grains to a lamellar structure, and the grain size in the ND decreased gradually. Finally, the average grain size in the ND was 0.31 μm. Additionally, the fraction of HAGBs increased after the third pass, resulting from the dynamic recovery and the shear bands. The texture evolution was tested by electron backscattered diffraction. After the fourth pass, the Al exhibited a combination texture of rolling texture and shear texture. The rolling texture components were composed of Copper{112}<111>, Dillamore{4 4 11}<11 11 8>, S{123}<634>, and Brass{011}<211>, and the shear texture components were Rotated Cube {001}<110> and {111}//ND. The microhardness of Ni, Ti, Nb, and Al was improved in the ARB process and finally reached 226.4, 246.3, 187.2, and 44.2 HV, respectively.