| High entropy alloys developed in recent years have become a research hotspot.Spark plasma sintering（SPS）,3D printing and other processes using powder as raw materials have become a new way to prepare materials.Nitrogen-containing high entropy alloy powders are prepared by gas atomization process and high-pressure nitrogen environment.CoCrFeMnNi high entropy alloy powder was prepared by gas atomization process.The effect of different atomization parameters on the particle size and nitrogen content of high-entropy alloy powder was explored,and high-nitrogen powder was obtained by static nitriding.The effect of nitrogen content on powder was studied,and the effect of nitrogen content on alloy properties was analyzed.The research shows that with the increase of temperature,the viscosity of high entropy alloys decreases gradually.When the atomization pressure increased from 2.0 MPa to 3.0MPa,the powder D50decreased from 83.2 μm to 56.8 μm,the nozzle diameter decreased from 1.3 mm to 1.0 mm,and D（50）decreased from 91.2 μm to 51.3 μm has a refining effect,and the chamber pressure has no great influence on the particle size.The larger the diameter of the powder,the more the satellite spheres are adhered,and the structures such as cellular crystals,equiaxed crystals and dendrites appear.The chamber pressure was increased from 0.3 MPa to 0.7 MPa,and the nitrogen content was increased from 0.233wt% to 0.354 wt%.The atomization pressure and nozzle diameter had little effect on the nitrogen content,and nitrogen was uniformly dissolved in the powder.Small bumps are formed on the surface of the powder,and the inside is a band-like structure.The bulk density is above 98%.With the increase of nitrogen,the hardness of the alloy increases from 549.7 HV to 632.4 HV,and the corrosion resistance in 3.5 wt%Na Cl solution is significantly improved,and two kinds of Cr-rich alloys appear.For the FCC1 and FCC2 phases,the grain size is decreasing.Figure 59;Table 10;Reference 50... |
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