Study On Production Technique Of Al-V Master Alloy

The aim of this work is to investigate the effects of melting temperature, holding time and cooling condition on microstructures of Al-4V master alloy. At the same time, the effect of different contents of V on the microstructures of Al-V master alloy is studied at same cooling condition.The chemical composition analysis, SEM energy spectrum analysis, XRD analysis and differential scanning calorimetry (DSC) analysis are used to find out the constitute different of phases of on Al-V master alloys, as well as the shape, the average size of the phases and their distributions. Besides, the mechanisms of the forming of these phases are also discussed. As a result, an optimal preparation technology for Al-V master alloy is obtained.The experiment includes three parts:(1) Find the optimization casting procedures to get a best microstructure.(2) Finding an optimization compositions are test to whether is suitable for Al-Mg-Si alloys.(3) Finding a best height temperature casting procedure of Al-V master alloys.The results show that there are two kinds of phases in Al-V master alloy, Al3V phase and Al21V2phase Al3V phase is a fine and dispersion particle while Al10V is a bulk blocky particle.The element V can dissolve into eventually phase when the master alloy is melted at1050℃for10minutes and a dispersive phase in master alloy is obtained mechanical stirry intervally, and solidified extreme, the diffusion of the phases of this kind of master alloy is improved.When content V in master alloy is less than2%, the fine Al10V phases appear and while the Al3V phases disappear at the same time. It is confirmed that Al3V is an effective phase which can refine the cast microstructure and Al10V is harmful to mechanical properties of the alloy, after inducing the Al-V master alloy into the Al-Mg-Si aluminum alloys. At a high melting temperature (≥1200C). the more disper Al3V phases are obtained at as-cast microstructure. However, the melting temperature is so high that the elements from mould will be enter into the melts, so introduce impurities into alloy. Therefore, the requirement for casting facilities is strict. At the same time burning loss of Al must be consideration.Over all, the optimal preparation condition of Al-V master alloy is that the melting temperature is1200℃and holding time is5minutes, and rapid solidification.