Microstructure And Properties Of Ni(75)Al(25) Composite Material Blended With Chromium And Tungsten Concentrate Powder Prepared By Laser Ignition Induced SHS

Ni(75)Al(25) alloy with excellent performance was prepared by laser ignition induced SHS, chromium powder and tungsten concentrate powder were appended to change the microstructure and mechanical comprehensive properties of Ni(75)Al(25) alloy. The microstructure was analyzed by OM、SEM、XRD and EDS, characterize the mechanical properties of hardness, wear resistance and corrosion resistance, etc. The effect of the content of chromium powder and tungsten concentrate powder on the microstructure and mechanical properties of sintered alloy was preliminary studied by author.The experimental results show that:the main product phase of Ni(75)Al(25) alloy are a-Ni、NiAl、Ni3Al and Al2O3, etc, sintered product organization composed mainly by the needle-like crystals and cellular dendrite; Add chromium powder after sintering alloy product of new Cr、Al4CrNi15 and Cr2O3 phase, needle-like crystal become small and gradually transformed into arborescent crystal and meshy crystal; Add tungsten concentrate powder after sintering alloy product of new Ni4W and WO3 phase, no significant change in morphology.After append chromium powder and tungsten concentrate powder, sintered alloy density, hardness, wear resistance increase within a certain range. When the content of chromium powder is 5%, the best comprehensive properties of the sintered alloy, the porosity is the lowest, which is 6.08%, the micro hardness is the biggest, which is 186HV10, the wear resistance as low as 0.84mg/mm2; When the content of tungsten concentrate powder is 1.5%, the best comprehensive properties of the sintered alloy, the porosity is the lowest, which is 6.38%, the micro hardness is the biggest, which is 183HV10, the wear resistance as low as 0.89mg/mm2; The NiAlCr alloy have no obvious increase in hardness and wear resistance by tungsten concentrate powder appended.The corrosion resistance of Ni(75)Al(25) alloy is improved by chromium powder and tungsten concentrate powder appended, the corrosion resistance of the alloy reduced with the reduction of the aluminum content; And the corrosion resistance of NiAlCr alloy is improved evidently.