al5tib及热处理对za102镁合金显微组织及性能的影响word格式论文.docxVIP

Al-5Ti-B 及热处理对 ZA102 显微组织及性能的影响INFLUENCE OF Al-5Ti-B AND HEAT TREATMENT ON MICROSTRUCTURE AND PROPERTIES OF ZA102 MAGNESIUM ALLOYABSTRACTIn 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 rodsor granular. The quantities of the ternary phase τ ( Mg32(Al,Zn)49) and binary phases becomes moreand 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 phase β- Mg17All2 separate out around the base and in the crystals after360℃×15h+180℃×15h heat treatment,which are dispersion in the base and reinforce the alloy.Smallphase β- Mg17All2、ternary phase τ ( 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℃×15haging 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