Study on the Microstructure and Properties of Laser Remelted Ceramic Coatings on Low Carbon Steel Surface

The plasma spraying Al2O3-13%TiO2 (hereinafter referred to as AT-13) ceramic coating on Q235B steel surface was dealt with laser remelting technique, then change of the microstructure and properties of the laser remelting AT-13 coating was studied. The experiment results show that the microstructure of laser remelted ceramic coatings is very dense, and no porosity appears. The main composition of laser remelted ceramic coatings is alpha-Al2O3 and a small amount of TiO2 and TiAl2O5. Micro hardness of AT-13 plasma spraying coating was measured with micro sclerometer and the maximum value of micro hardness HV0.2 was 998, while the maximum value of micro hardness HV0.2 of laser remelting coatings was 1710; Bonding strength of AT-13 plasma spraying layer was measured through the tensile test and the average value is 24.36 MPa, while bonding strength of laser remelting coating was more than 68.8 Mpa. The wear resistance of laser remelting coatings is higher than that of AT-13 plasma spraying layer through the pin dish particle attrition test.