Influence of coating thickness on the morphology of TiC particles

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.

KEYWORDS:

• TiC/Al-based composite coating
• AZ31B magnesium alloy
• cladding layer thickness
• γ-Al₁₂Mg₁₇
• β-Al₃Mg₂

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research is supported by National Nature Science Foundation of China [grant number 51275342 and 51405334].