Research On Forming Uniformity Of Ti6242s Alloy Compressor Disk Of Aeroengine

The aero engine includes a large number of disk parts,which need to work under high temperature,high pressure and alternating load for a long time,so their microstructure uniformity requirements were extremely high.Such forgings often fail to ensure the uniformity of microstructure due to the unreasonable preform blank and forming process,thereby affecting the performance of the forgings and the safety of the engine.With the rapid development of the national aviation industry,especially the independent development of a new generation of fighters and large aircraft,higher requirements were placed on the performance stability of aero-engine-related rotating parts.Therefore,the forming process optimization and deformation uniformity of the disk forgings were studied to ensure the actual production of forgings with reasonable deformation,uniform microstructure and stable quality,which had great engineering application value.In this paper,a compressor disk forging of aeroengine made of Ti6242s alloy was taken as the research object.The high-temperature plastic deformation behavior of the forging material,the type characteristics of the forgings and its preform blank design methods,and the optimization of the forming process have been studied.The main research work has the following points:?1?The isothermal compression test of Ti6242s alloy was carried out on a Gleeble-3500 thermal simulator at the temperature range of 900-1100?and the strain rate range of 0.001-10s^-1.The true stress-strain curves of the alloy under different deformation conditions were obtained and the effects of deformation conditions on the flow stress of Ti6242s alloy were analyzed.Based on this,the constitutive equation of Ti6242s alloy in?+?two-phase region and?single-phase region were established,which lays a theoretical foundation for numerical simulation analysis;?2?Based on several aero-engine disk forgings whose pre-forming schemes were verified by the numerical simulation and actual production,the relationship model between preform blank height and forgings height,preform blank diameter and forgings diameter were established respectively.According to the similarity of shapes and structures,these disc forgings were further classified,and reasonable preforms were designed for each type of forgings.Finally,the preform blank design methods aimed at the deformation uniformity of disk forgings were obtained through analysis and summary.?3?Aiming at the problems of uneven deformation and partial performance failure of the compressor disk forgings under former process,the deformation areas were divided under the guidance of the above preform blank design methods,the deformation uniformity of the forgings was optimized from three aspects of preform shape,forgings structure and heat preservation process,and a new forming scheme for the compressor disk forgings was obtained.The effective deformation area of the forgings was increased from 45.8%to 79.5%by optimization,and the large deformation area and the small deformation area was reduced by 28.4%and 5.3%,respectively.The deformation uniformity of the forgings was significantly improved;?4?The numerical simulation optimized process was verified by the actual trial production,and the test results show that the forgings have good microstructure uniformity and the mechanical properties have reached the requirements of relevant standards.