Effects of Al2O3 addition on the microstructure and properties of CoCr alloys

Abstract

Aluminum oxide (Al2O3) powder can be added to typical cobalt-chromium (CoCr) alloy powders. In the present study, we successfully prepared alloyed samples of various powder ratios by laser cladding and analyzed their microstructure and carbide structural characteristics, including the microhardness, biological properties, morphology (using scanning electron microscopy), and crystal structure (using X-ray powder diffraction). The elemental distribution was also determined by energy-dispersive X-ray spectroscopy. The results showed that an Al2O3 addition caused the alloy microstructure to change from slender columnar crystals to columnar grains that were similar in shape to equiaxed grains. In addition, Al2O3 agglomeration zones appeared, and carbide structures were altered. The mechanism of the observed performance changes was also analyzed.