LAUSR

ABSTRACT The TiC/Al-based composite coatings with different thickness were fabricated on the AZ31B magnesium alloy by laser cladding. The distribution of TiC ceramic particles in the cladding layers was not uniform, and the reunion degree increased with the increase of cladding layer thickness. The cladding layers mainly contained Al, γ-Al12Mg17, β-Al3Mg2, and TiC phases. γ-Al12Mg17 mainly distributed in the bottom of the cladding layers, and β-Al3Mg2 distributed in the middle and surface zones. The contents of γ-Al12Mg17 and β-Al3Mg2 have the inverse proportion to the thickness of the cladding layers, and the TiC content is irregular. The micro-hardness value was increased with the increase of the cladding layers thickness, and the thicker the cladding layers, the greater the fluctuations of the micro-hardness. The wear resistance of the cladding layer had the positive proportion to the hardness. TiC ceramic particles could cause the exfoliation in the wear test.