Research On Forging Process Of NiAl Ribbed Plate Under Continuous Pulse Current

With the continuous improvement of the requirements for high-temperature structural materials of spacecraft,NiAl intermetallic compounds with excellent high-temperature properties and low density have been widely concerned.NiAl materials have high high temperature strength,high temperature deformation resistance,and difficult to form;and traditional furnace heating high temperature forming energy consumption is high,easy to oxidize,equipment loss is serious,which greatly limits its application and promotion.Based on this topic,a pulse current heating auxiliary forming device and process for NiAl non-dense body preforms are proposed.The microstructure evolution and deformation mechanism of NiAl non-compact material during pulse current heating forging are investigated.It is a new type of green and green component.The high temperature forming process provides experimental and theoretical basis.Firstly,NiAl non-dense material was prepared by hot pressing sintering of Ni and Al powders.According to the Gleeble thermal compression experiment of sintered materials with different densities at a certain temperature and strain rate,the optimum material high temperature performance of the subsequent forging forming experiments was determined.Secondly,the device system and process flow of the pulse current heating forging experiment are designed.Select the insulating spray metal die and the laminar ceramic punch combination die with better forming effect;determine the temperature and strain rate during the forming process through experiments such as hot compression test,self-resistance heating,electric heating and electric heating stretching.Process parameters such as current density,duty cycle and frequency.The finite element simulation of the high temperature forming process of NiAl ribbed plates was carried out,and the deformation rate of the forming process was explored,and the feasibility of the process was verified.Based on the above process flow and parameters,the pulse current heating forging experiment was carried out to obtain the NiAl reinforced plate member.Finally,the microstructure evolution before and after the pulse current treatment and the pulse current heating forging were observed,and the deformation mechanism was analyzed.Compared with the traditional furnace heating,the pulse current reduces the grain size,the microcrack healing and the microscopic pore size shrink;the pulse current heating forging shape makes the grain more refined,and the micro crack and hole defects are further improved.Pulse current processing and pulse current heating forging process have recovered and recrystallized,further promoting its deformation behavior at high temperatures.The experimental methods and process flow proposed in this paper provide theoretical guidance and experimental basis for the pulsed current heating forging of NiAl reinforced members.