Effect of Microstructure and Mechanical Properties of Cast
Aluminum Alloys by Adding Carbon Powder

R. Li†‡, L. J. Chen, Q. Zeng, & H. Gao

ABSTRACT: Optical microscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction were performed, meanwhile, tensile tests and several other test methods were used to study the microstructure and mechanical properties of cast aluminum (Al) alloy with and without added carbon powder. The results show that carbon powder can indeed be added into the alloy system and existed in the form of carbon compounds. The alloy with added carbon powder exhibits elongation nearly three times compared to the one without carbon; however, its strength do not reduce significantly. Moreover, the results indicate that silicon carbide is generated when carbon powder was added into the molten Al alloy. It not only refines the grains, but also results in the alternate appearance of plastic strain and elastic strain during tensile test. Furthermore, with the increase in plastic deformation, elastic mutant cycle gradually became longer, and the material ductility is better than traditional aluminum alloy.

Keywords : Carbon powder; Cast aluminum alloy; Plastic deformation; Silicon carbide.