High velocity oxygen fuel has been used as fabrication technique for manufacturing aluminium coatings reinforced with different weight percents of silicon carbide particles on Mg-Zn alloys used as substrates. The aim of the investigation is to improve the tribological performance of the ZE41A magnesium alloy. The parameters of the thermal projection system have been optimized in order to maximize the SiC particles incorporation in the aluminium matrix of the coating. Pin-on-disc tests were developed to characterize the tribological behavior of the different specimens. Minor degradation of the magnesium alloy was achieved after . Composite coatings with thicknesses of about 120 µm, reinforced with about 10 wt.% and with high adhesion to the substrate were achieved. After the coating parameters were optimized, the wear rate of the magnesium with the composite coatings decreased by two orders of magnitude in comparison to that of the uncoated magnesium alloy.

SiC-reinforced Al-12Si alloy coatings were produced using the Cold Gas Dynamic Spraying deposition process. Feedstock powder mixtures containing 20% and 30% vol. of particulate SiC were used. The composite coatings’ bond strengths and microstructures were evaluated, as well as the porosity and the SiC content. It was found that approximately 45% of the SiC particulate blended with the aluminum alloy was embedded in the coatings. The SiC was homogeneously distributed inside the Al-12Si matrix. Particle velocity measurements revealed that the addition of up to 30% vol. of SiC did not change the Al-12Si particle velocities.

The SiCp/Al composite was fabricated by a plasma spraying technique. By mean of OM SEM, TEM, XRD, SAED, EDS techniques, the microstructures for sprayed SiCp/Al composite were investigated in detail. The composite consisted of SiC and Al, along with single crystal Si and amorphorous Si, and tiny Al 2 O 3 . On the whole, the interfaces between SiC particle and Al bonded well, and tiny reactants like Al 2 O 3 can be found near the interfaces. The mechanisms of chemical reactions were given during spraying. The nano-Al grains and nano-Al particles were seen in the sprayed composite. The formation mechanism of nano-Al grains and particles of SiCp/ Al composite was explained. Some interface relationships existed in the sprayed composite.