Establishment Of Constitutive Model Of The Semi-solid ZK101Alloy In The Micro-forming Field And Research On The Key Technology Of The Micro-gear Extrusion

This paper successfully combine the semi-solid metal formingtechnology and the micro-plastic forming technology together. Based on theproperty research of the semi-solid ZL101alloy, this paper manufacture themicro solar gear with complicated shape utilizing the micro semi-solidplastic forming technology. The details can be summarized as below:1.The isothermal compressive experiment is used to study theinfluence of the temperature and the strain rate on the yield stress of thesemi-solid ZL101alloy. Based on the Arrhenius model, a new constitutivemodel is established with the help of the gene algorithm (GA) to fit andoptimizing the experimental on the Matlab software. The compressivesimulation has been applied on the DEFORM-3D platform using theestablished constitutive model. And the results show that the accuracy isquite good especially at the temperature range from the570oC to590oC,and the temperature range from0.01to0.05S-1.The maximum error is8.0%.2. A micro thixo-forming extrusion system has been created to extrudethe micro solar gear. It is composed of the micro extrusionmold、semi-solid reheat controlling system and CMT4000general testingmachine. It has extruded the micro solar gear with good quality under thetemperature range from560℃to570℃,and the extrude velocity range from0.5mm/min to2mm/min. The influence of the extrusion velocity andtemperature on the steady load of the micro solar gear extrusion process hasbeen studied carefully. The distribution of the effective strain、effectivestress and the velocity field has been achieved through the extrusion processsimulation on the DEFORM-3D platform. And the comparison of the load-stroke curves between the simulation results and the experimental datashows the accuracy of the established constitutive model of the semi-solidZL101alloy.3. The microstructure of the cross and the longitudinal section of themicro solar gear have demonstrated the scene of the liquid segregationduring the forming process.