Selective Laser Melting of 3D-Printed FeSiAl Microwave Attenuating Material:An Experimental Study

We addressed the selective laser melting(SLM) of 3 D printed FeSiAl microwave attenuating material for fabrication of advanced microwave vacuum electronic devices.The influence of 3 D printing and SLM solidification conditions,including the grain-size/mass-ratio/thickness of FeSiAl powder,preheating temperature and power/scanning-speed/scanning line-width of laser beam,on the microstructures,microwave attenuation and mechanical properties of the FeSiAl pattern was investigated.The results show that the printing and solidification conditions all had a major impact.For example,the optimized conditions included:grain-size of 200 mesh,Fe∶Si∶Al∶O mass-ratio of 74.63∶11.64∶3.36∶10.37,thickness of 0.02 mm,laser beam power of 175 W,scanning speed of 1600 mm/s,scanning line-width of 0.06 mm,and preheating temperature of 80℃.The FeSiAl pattern,formed by 3 D printing and SLM solidification under the optimized conditions,displays good attenuation properties and meets the requirements on design/fabrication of microwave vacuum electronic devices.