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The equiatomic CoCrFeNiMn high entropy alloys (HEAs) has been successfully manufactured using direct laser deposition (DLD) technique. The size and number of porosities, the microstructures along the height of samples and the tensile properties of DLDed HEAs prepared under room (293 K) and cryogenic temperatures (77 K and 200 K) were investigated. The results show that DLDed HEAs exhibit directional solidification, forming dendritic columnar grains with long pores at the grain boundary in bottom regions and transiting to equiaxed grains close to top regions. And in the top regions, the pores are round and the numbers are greatly reduced. Compared with tensile properties of DLDed HEAs, the 77 K tensile samples cut from the top region have better performance, but the elongation of 293 K tensile samples in the middle region and 200 K tensile samples in the bottom region are similar, owing to the difference of porosity and microstructure in the two regions.

In this study, a new wire + powder synchronous arc additive manufacturing technique was used to manufacture Ti-Cu alloys. The microstructure and properties of the as-fabricated alloys were studied. The results showed that the prepared Ti-Cu alloys have good properties. The Cu with high growth restriction factor can increase the constitutional supercooling zone in the Ti-Cu alloys, which can override the negative effect of a high thermal gradient in the manufacturing process. Through the observation of the microstructure, the as-printed Ti-Cu alloy specimens have equiaxed fine-grained microstructure. Through corrosion performance analysis, the Cu can also make the passivation film of the alloy more compact and make the alloy more corrosion resistant., Competing Interests: No conflict of interest exists in the submission of this article, and the article is approved by all authors for publication., (Copyright 2024, Mary Ann Liebert, Inc., publishers.)