Abstract:The effects of different casting moulds on the microstructures and mechanical properties of ZTC4 titanium alloy were studied. The effects of cooling rate, solidification rate and solidification time on the microstructures and mechanical properties of ZTC4 titanium alloy were studied by numerical simulation and experimental analysis.The results show that compared with the ceramic sample, the graphite sample has better heat dissipation effect, faster cooling speed and higher solidification speed, which makes the microstructure of the sample to be fine lath martensite alpha produced by quenching, with smaller grain size, more orientation and larger solidification thickness.The yield strength, tensile strength and hardness of the mechanical properties increased by 6.7%, 2.6% and 4.2% respectively, but the elongation and section shrinkage decreased by 37% and 34.5%, respectively. At the same time, different positions of the same mold have some influence on the cooling rate. The cooling rate at different positions of the sample is in the order of middle > bottom > top.