Based on the principle of rapid casting and selective laser sintering（SLS）technology

an investment casting test model of ZTC4 alloy was established.The temperature field and solidification process were analyzed by the ProCAST finite element analysis software

and the grain structure and grain growth were analyzed by CAFmodule.Meanwhile

the microstructure was characterized and mechanical properties were measured by SEM

EDS and tensile testing.The results reveal that adopting the bottom gating system with vacuum pouring

the solidification sequence presents from outside to inside without slag inclusion defect inside.The cooling rate at the top of the sample is lower than that at the bottom

and the average cooling rate is 1.26℃/s.Widmanstatten structure mainly composed of whiteαphase

blackβlamellae andαphase at the grain boundary is distributed at the micro level.Larger grain size affects the mechanical properties

presenting high strength and low plasticity.The average yield strength and tensile strength of the alloy reach 785.67 MPa and 937.55 MPa

respectively

and the elongation and section shrinkage rate are 14.83% and 19.33%

respectively.The comprehensive properties meet the requirements of GB/T 6614-2014 national standard for titanium and titanium alloy castings and industrial production.