The investment casting process is used to produce 100 rod-shaped titanium alloy castings in batches. The cast titanium alloy castings are not subject to hot isostatic pressure. The one-time flaw detection qualification rate of the castings is 98%, of which 2 products have one high-density inclusion defect at the large wall thickness ratio of the rod opening, and 100 products have a one-time fluorescence qualification rate of 100%. The full-size inspection of the castings meets the requirements of the drawing, reducing the production cost of the rod-shaped titanium alloy castings.
(1) Taking the rod-shaped titanium alloy casting as the research object, the temperature field and stress field of different casting process schemes are simulated by numerical simulation method, the shrinkage and stress are analyzed, and the casting process scheme is simulated and optimized. It is determined that the gating system designed by the equilibrium theory is the most suitable for rod-shaped titanium alloy casting with rod length and rod width ratio greater than 9.
(2) When using the proportional solidification theory to design the gating system, it is not suitable to introduce the investment casting hot spot at the position where the wall thickness ratio has little difference; Because the feeding distance of titanium alloy is relatively short, the gating and riser feeding is suitable for the parts with large wall thickness.
(3) Batch production is carried out according to the optimal investment casting process scheme of numerical simulation, and the process production parameters are set according to the boundary condition parameters of numerical simulation. The internal flaw detection quality of batch production investment castings is consistent with the simulation results, and the residual stress represented by fluorescent cracks is consistent with the simulation results.