| NiAl intermetallic compound has a high melting point, low density, good thermalconductivity, high oxidation resistance and a series of excellent overall performance isconsidered to be highly competitive potential of high-temperature structural materials,and to get people in harsh conditions such as high temperature wide range ofapplications.Selecting Ni, Al pure powder, design different ingredients point, and addingdifferent content of tungsten concentrate powder and pressed into a preform. Using laserignited self-propagating combustion synthesis technology by Al thermal reductionreaction in situ particle enhanced Ni-based composite materials. Using OM, SEM, XRDand EDS analysis of the microstructure and structure, hardness, wear resistance andcorrosion resistance testing. Investigated doped tungsten concentrate powder contentand the laser sintering process parameters on the structure and macroscopic properties ofNi-based composite microstructure.Experimental results show that: not add tungsten concentrate powder Ni-Al-basedalloys, non-equilibrium phase Ni3Al, NiAl and Al2O3, sintered product organizationcomposed mainly by the needle-like crystals and cellular dendrite; add tungstenconcentrate powder after sintering alloy product of new Ni17W3Ni4W and WO3phase,needle-like crystal becomes small and gradually transformed into crystalline cellular;increase in the content of tungsten concentrate, sintered alloy hardness, wear andperformance increase within a certain range, weakly reduces the corrosion resistance ofthe sintered alloy, the increase in the laser power the comprehensive performancesintered alloy can be increased; when component point of Ni75Al25, the sintering poweris1100W, the best overall performance of the sintered alloy, and its relative density was5.75g/cm3, a porosity of7.6%, the sintered alloy hardness610.5HK wear rates as low as0.22mg/mm2; preferably, the corrosion resistance, the passivation interval reached1100mV. |
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