Study On The Plastic Deformation Behaviour And Numerical Simulation Of Forging Process Of Ti/Al Powder Compact

TiAl based alloys are widely studied on the account of low density, hightemperature and oxidation resistance. However, the use of TiAl based alloys islimited due to their poor plasticity, giant resistance of deformation. Therefore, it ishard to prepare TiAl based alloys that can meet high density, high performance, lowcost and complexity of the parts forming requirements by traditional hotdeformation processing, powder metallurgy and casting forming. Aiming at thedifficult machining of TiAl based alloys, a new technique, which includesmechanical mixing, compression and sintering was proposed. Compared to TiAlbased alloy, Ti/Al powder billet has the characteristics of better plastic and beingeasy to shape. By low temperature sintering experiment and compression test, theoptimal sintering is determined. And the plastic deformation behaviour of Ti/Alpowder compact is studied. The forging processes of Ti/Al powder compact havebeen simulated by ABAQUS to provide a reference for the Ti/Al powder forgingprocess parameters set and the optimal design.Ti and Al powders were mechanical mixed and then making perform. Sinteringthe billets at low temperature by different sintering process. By SEM, EDS, X-Rayobservation, the microstructure was investigated. By hot compression test theplastic deformation behaviour of Ti/Al powder compact is studied and establish theconstitutive relationship equation and the processing map. The forging processes ofTi/Al powder compact have been simulated.The preparation process of Ti/Al powder billet has been investigated. Byanalyzing the energy spectrum and X-Ray, it can be drawn that what the product iswhen the temperature and holding time changed. By high-temperature compressiontest, the plastic properties were studied and analyzed to determine the optimalsintering.Isothermal compression test is conducted on powder compact with differentrelative density. The influence rules of relative density, temperature, strain rate onthe flow stress have been studied, thus the constitutive equation of Ti/Al powdercompact is developed, and the optimal forging processing parameters is obtainedbased on the processing map and microstructure analysis.The forging processes of Ti/Al powder compact have been simulated by theABAQUS. The distribution and change of equivalent stress field, strain field andrelative density are analyzed. The influence rules of temperature, strain rate on theforging process have been studied.