1 Department of Materials Engineering, Hebei College of Industry and Technology, Shijiazhuang 050091，China, 2Advanced Material & Technology Institute, University of Science and Technology Beijing, Beijing 100083, China
Abstract：Ti-Al2O3 tubular porous skeleton with porosity as high as 75% was prepared by gel centrifugal forming process and vacuum sintering using sucrose as pore-forming agent. The prefabricated Fe alloy melt was vacuum pressureless impregnated at 1 400 ℃ for 30 min. Finally, a small composite roller with iron-based alloy core and Fe-TiC-Al2O3 surface was prepared. The microstructure and phase composition of the surface layer of the composite roller were tested and analyzed by scanning electron microscope and X-ray diffractometer, and the hardness, thermal shock resistance and wear resistance of the composite roller were measured. The results show that the core and surface layer of the prepared composite roller are well bonded without cracking. TiC is produced by reaction between Ti and C during infiltration. TiC is formed around Al2O3 particles to form an annular phase. The hardness of the surface layer reaches 65 HRC, and no obvious cracks appear after 10 thermal shocks at 800 ℃, while cracks appear in the surface layer near the bonding surface after 20 thermal shocks and spread along the bonding surface. In the wear test, Al2O3 particles are well bonded to the matrix without peeling off.
2019, Vol. 29 
