Compatibility Of Deformation In Tial Alloy Canned-Forging And Numerical Simulation

TiAl alloy is a new high-temperature structural material, characterized with low density, high strength and modulus.And it is considered as ideal material in Aerospace field.However its brittleness and bad plasticity at room temperature make it difficult for further development.It is found that obtaining the finer TiAl alloy structure can improve its comprehensive property.Nowadays thermal mechanical treatment technique is used to acquire homogeneous and much finer structure,which includes forging and extrusion.When forging TiAl alloy, if operating unproperly it easily leads to shortage of thermoplasticity and crack. When extruding TiAl alloy, the property of die must be good enough to meet some standard requirement, and after experiment the sample can not be easily dissambled, which cost highly. Based on these shortcoming the TiAl alloy canned-forging is proposed, which can be easily done with commen hydraulic press and keep the TiAl alloy in the state of near-isothermal and can effectively make the coarse lamella of TiAl alloy ingot much finer.Based the TiAl canned-forging as main content,this paper has analysed its flow process theoretically, studied its mechanical state, present the concept of deformation compatibility and computation model,calculated deformation force and thickness.of can.By FEM software DEFORM-3D, the canned-forging proecess and effective strain field under different thickness and ratio of height to diameter (H/D) have been discussed. It is intuitively found that when H/D is 1 and thickness is growing larger, the compatibility is better, when H/D is 2, the instablity of sample has been found.According to the experiment of TiAl alloy canned-forging, the H/D of TiAl is choosed as 1:1,1.5:1,2:1 respectively and the thickness of can is choosed as 3mm, 5mm, 8mm respectively, it is found that when the H/D is 1:1, the compatibility becomes better with the thickness growing. When the H/D is 2, the instability to a greater or less extentt happened. By comparing the experimental results and simulated ones, it is found that they both basically match each other when H/D is 1:1.