The effects of annealing temperature and cryogenic holding time on the microstructure and mechanical properties of SLM-formed ZL114 Aalloy were investigated by OM

SEM

EDS and tensile testing.The results demonstrate that after 230℃×2 hannealing treatment

the elongation of the alloy is increased by 18.04%

while the tensile strength is decreased by 2.94%

and annealing treatment at 300 ℃ ×2 hresults in a decrease of28.19%in tensile strength and 4.55%in elongation of the alloy.The annealed microstructure of the alloy presents a large number of pores at the junction ofα-Al and Si phase.Cryogenic treatment（-196℃）can significantly improve the mechanical properties of SLM-formed ZL114 Aalloy

where the holding time of 36 hhas the best effect.Compared with the those of deposited state ones

its tensile strength and elongation are increased by 18.99%and23.03%

respectively.The cryogenic eutectic Si is more evenly dispersed in the matrix and transformed into a rodlike structure

which significantly enhances the plasticity of the alloy.