Research On Numerical Simulation Of Stress And Deformation Of Ti47Al2Cr2Nb Alloy Castings

With the development of the aviation industry, the performance of high-temperature alloys have become increasingly demanding. TiAl-based alloy as an intermetallic compound, have the performance of both metals and ceramics. They have the advantages of high specific strength, high melting point and high modulus, good high-temperature oxidation and anti-retardant properties, which good meet the requirements of aerospace structural parts to be heat-resistant performance, but also they have defects. They are poorly stretched, difficult to filling other characteristics of complex parts, especially for the thin-walls, which could be cracking and deformed in casting .In this paper, the state of the stress and deformation of the casting is simulated by the casting simulation software-ProCAST during investment casting of Alloy. Creat the database of Ti47Al2Cr2Nb needed in simulation, including the thermodynamic properties and mechanics properties, by experiments and searching for papers. We simulate the thermal stress and deformation of a typical stress frame, then we do experiments to compare after simulating pouring casting. On this basis, we design and optimize the process of the investment casting of a thin-walled tubular part.The factors affecting the stress state and deformation, such as pouring temperature, preheating temperature of the ceramic shell, rotation speed of centrifuge casting, are studied in this paper. The results indicated that based on completely filling under the conditions of the casting, lower alloy pouring temperature, high preheating temperature of the shell, an appropriate increasing of rotation speed of centrifuge casting can reduce the effective internal residual stress of the casting, also could reduce the possibility of hot tearing in high temperature phase. A high preheating temperature of the shell affect it most, pouring temperature less impact than preheating temperature of the shell, followed by rotation speed with minimal impact. The results of comparative analysis of actual casting and simulation results are basically consistent.we design and optimize the process of the investment casting of a thin-walled tubular part by simulations. We design different casting systems, and analysis different casting process parameters, especially to the cracked parts. Finally we get optional parameters with preheat temperature of shell of 500℃, lower pouring temperature(a super heat of 90℃), the top gating system, centrifugal cast with a rotation speed of 180r/min.