Microstructure and hardness of laser clad SiCp–Al composite coatings on Al alloys
2008; Elsevier BV; Volume: 62; Issue: 17-18 Linguagem: Inglês
10.1016/j.matlet.2008.02.041
ISSN1873-4979
Autores Tópico(s)High-Temperature Coating Behaviors
ResumoSiC reinforcing Al–Si coatings were fabricated on AlSi12 substrate by laser cladding using powder mixture of Al–12Si alloy and SiC. Microstructure and microhardness of the coatings were examined. The results show that, the coatings are divided into two sub-layers, the upper layer consists of needle-like primary Si, Al–Si eutectics, α-Al dendrites and small amount of SiC particles, and there are α-Al dendrites, Al–Si eutectics and many SiC particles in the bottom layer. Orientated growth dendrites and columnar grains, which are almost perpendicular to melting surface of the substrate, are observed in the bonding zone. The microhardness of the coatings is approximately 220∼280HV, 2–3 times as that of the AlSi12 substrate.
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