Influence Of Al-5ti-b And Heat Treatment On Microstructure And Properties Of Za102 Magnesium Alloy

In this paper, influence of Al-5Ti-B and heat treatment on microstructure and properties of ZA102 magnesium alloy is studied.The microstructure is observed by using the optical microscopy and scanning electron microscopy (SEM).Using X-ray diffraction analysis (XRD) test the composition of the precipitated phases. Using DSC curve analyses the precipitation dynamics of the alloy. Using the corrosion testing instrument take the electrochemical corrosion testing to analyse the corrosion resistance of alloy,by drowing the polarization curves.The results show that: the Al-5Ti-B can make test alloy grain refinement, change of precipitation Mg17Al12 beta way and form, by continuous exhalation into intermittent separation by reticular into short rods or granular. The quantities of the ternary phaseτ( Mg32(Al,Zn)49) and binary phases becomes more and more. Ti2B5 is a new phase separating out the alloy. But when Al-5Ti-B > 0.4% percent of the amount of grain, magnesium alloys are thick tendency. The alloy hardness obviously increases after add in 0.4%Al-5Ti-B but also. The phaseβ- Mg17All2 separate out around the base and in the crystals after 360℃×15h+180℃×15h heat treatment,which are dispersion in the base and reinforce the alloy.Small phaseβ- Mg17All2,ternary phaseτ( Mg32(Al,Zn)49),granular phases Mg3Sb2 and Al4Cu9,new phases MgB6 and Ti2B5 separate out around the base after 360℃×15h+80℃×20h+180℃×15h aging treatment, which are hard particle and dispersion. The precipitated phases are very hard, dense and even–textured after twin-stage aging, which contribute to the increase of the mechanical property.Comparing the erosion resisting properties of the alloy after different heat treatment, we know that: the morphology is well-distributed, the precipitated phases are dispersion, the impurity element well dissolve in the base, for what we gain a better erosion resistance.The corrosion current density is 2.58×102μA·cm-2.