Study of Aging Treatment on the Coating with 3%Cu/Fe-based Alloy Fabricated by Laser Cladding

The composite coating with 3%Cu/ Fe-based alloy was fabricated on Q235A steel by laser cladding. The effect of aging treatment on the microstructure and properties of laser-cladded coating was investigated. The results show that there is alpha-Fe phase accompanied by the M7C3 with an orthorhombic crystal structure and M23C6 in the cladded coating. The preferred direction at (110) crystal plane exist in the alpha-Fe. The TEM observation shows that the high density dislocations exist in the martensite. When the cladded coatings are aged at 550 degrees C for 20 h and 30 h respectively, the epsilon-Cu particles precipitate dispersedly from the supersaturated alpha-Fe solid solution along the M7C3. The epsilon-Cu particles play the role of anchoring dislocation. The microhardness and the wear resistance of coatings are increased greatly after the aging treatment. The coating aged for 20 h at 550 degrees C presents the best wear resistance in the tested coatings. With aging time, the microhardness and the wear resistance of cladding coating are decreased.