Research On 3D Printing Of Ceramic Particle Reinforced Iron Matrix Composites

FeCrAl alloy has excellent high temperature oxidation resistance and strength,and has great application prospect in the field of corrosion resistance and high strength structural materials.At present,research on additive manufacture of FeCrAl alloy and ceramic reinforced FeCrAl alloy composites has rarely been reported.There are currently little research on selective laser melting(SLM)processing of FeCrAl related materials,so the related research on FeCrAl material system development,SLM processing parameter optimization,microstructure analysis,and mechanical properties testing need to be carried out as soon as possible.In this study,Fe20Cr5 Al was selected as FeCrAl alloy matrix,and conventional WC,spherical casting WC(CC),and TiB2 were used as reinforcement phases for SLM processing of ceramic reinforced FeCrAl matrix composites.The correlation models between SLM process parameters and relative density of Fe20Cr5Al-10 vol.% TiB2?Fe20Cr5Al-20 vol.% WC?Fe20Cr5Al-20 vol.% CC were respectively established via surface response experimental design system.The optimum SLM processing parameters have been obtained based on these models and the corresponding relative density reaches0.961-0.975.Microstructure analysis for SLMed Fe20Cr5Al-10 vol.% TiB2 composite showed that there is no noticeable reaction between TiB2 and matrix.TiB2 plays an important role in refining and strengthening the matrix.At the same time,significant diffusion of Ti and B elements from TiB2 into the matrix results in solid solution strengthening.For SLMed Fe20Cr5Al-20 vol.% WC composite,there is significant WC reaction with the matrix resulting in the formation of Fe3W3 C at WC-matrix interface.In addition,there is noticeable W and C diffusion from WC particles into the matrix,which significantly increases the strength of the matrix,but also reduces the plastic deformation ability of the matrix.SLMed Fe20Cr5Al-20 vol.% CC composite still maintains the CC particles with high sphericity in the matrix,with some CC particles broken under the direct or indirect action of laser.There are obvious reaction between CC and matrix to form Fe3W3 C mesphase.Meanwhile,W and C diffuse significantly into the matrix,resulting in the significant reduction of plastic deformation ability of matrix.As compared with SLMed pure Fe20Cr5 Al,the reinforcements of TiB2,WC,and CC lead to the improvements of hardness by 55.6-126%,compressive strength by 82.7-107%,and wear resistance by 360-900% for SLMed Fe20Cr5Al-ceramic composites.