The Research On The Forming Process Of Fixed Vortex Disk Of Aluminum Tungsten Powder Alloy

Recently, the automotive industry as one of China’s pillar industries has gained rapiddevelopment. With the continuous improvement of people’s living standards, people’srequirements for cars is also rising，especially for the requirements of car’s comfort, whichprompts the car air conditioning becomes one of the indispensable parts of the cars and alsomakes the scroll compressor be favored by most people. As an important component of thescroll compressor, the fixed vortex disks are required to have low density, good plasticity andwear resistance to have a long service life. Therefore, to seek a suitable material andworkpieces with a high precision plastic processing has become an important facing issuecurrently.In this paper, the forming experimental process of the fixed vortex disks was studied byusing the aluminum purity of99.7%, the tungsten powder purity of99.8%as raw materialand the finite element simulation. The main works carried out were as follows：(1) It could be seen from the aluminum tungsten alloy phase diagram that there waslittle solid solution phase. Combined with the density, melting point and other properties oftwo kinds of powder, the aluminum tungsten alloy powder of super solid solution wasprepared by using95%aluminum powder mixed with5%tungsten powder with the methodof mechanical alloying.(2) The cold billets of116mm were gotten by using the powder obtained above withthe method of the unidirectional pressing way in the rigid modulus at room temperature. Themain technical parameters of the pressing process were studied, including pressingpressure, pressing speed, holding pressure time and lubricating condition and so on. Due tothe large internal voids, low density and undesirable edges forming of the cold billets, thecold billets obtained were then sintered and pressed by the method of hot pressing. The mainprocess parameters of the hot pressing process were also studied, including pressing pressure,compression speed, dwell time, lubrication conditions, sintering temperature, holding time and so on.(3) Based on the high temperature compression tests of Al-W powder alloy conductedon the Gleeble-1500thermal mechanical simulation, with the respectively strain rate of0.001、0.01、0.1、1s-1and respectively deformation temperature of450、480、510℃, the truestress strain curve in deformation was obtained. In this paper, the Fields-Backofen constitutivemodel was used and the softening factor was introduced to fit the measured stress-strain curvewith the constitutive equation. The results obtained through the constitutive equation can becalculated in good agreement with the experimental data.(4) The energy dissipation map of aluminum tungsten powder alloy was obtained byusing MATLAB software and Murthy decision criteria. It was found that the energydissipation map of the alloy was basically the same at different strain and theinstability region was expanding with the increase of strain. It was also found thatthe instability phenomenon appeared at relatively high strain rates. Combined with the energydissipation rate and the unstable region, the security processing zone and the optimal processparameters of thermal deformation of the alloy were obtained.(5) The forming process of the vortex disk was studied by using the Simufact software.The simulation results showed that a suitable counter pressure could significantly improve theaccuracy and section flatness of the parts. Then the experimental research on the andthe vortex disk from the billet to final forming process was carried out. The result was inagreement with the result of finite element simulation, and the parts meeting the requirementsof accuracy and performance were achieved, which verified that the experimental programand proposed forming process was feasible.