Inoculant Of Al Matrix Composite Inoculate Al-Cu-Mn Alloy

Aluminum alloys have been widely used in the area of aerospace,military and automobile due to its low density,high strength to weight ratio,high fracture toughness,good corrosion resistance and good fatigue resistance and so on.To further improve the properties of aluminum alloys,many methods have been employed by scholars at home and abroad.Among these methods,grain refinement by adding inoculants is the most simple and effective one.In addition,the addiition of rare earth elements or transitional elements are also an important stept to enhance the properties of aluminum alloy.In this study,three types of inoculants were prepared by a method of melt reaction.The refining effect of these inoculantion to Al-Cu-Mn alloys and refining mechanism were analyzed in detail.Meanwhile,the combined action of microalloying and inoculants on the microstructures and properties of Al-Cu-Mn alloy were also investigated.The master alloy inoculants of Al-Ti-B,Al-Ti-B-Y and Al-Ti-B-C-Y were prepared successfully by a melt reaction method and vacuum quenching process.The phase structures of the inoculants were identified by X-ray diffractometer.The microstructure of the as-cast master alloy inoculants and the ribbon-like inoculants were observed by SEM.The three types of master alloy inoculants that were ribboned to the Al-Cu-Mn alloys and the refining effect on the alloys was observed with metallographic microscope.The results show that all the three types of inoculants can refine the Al-Cu-Mn alloy,and the Al-Ti-B-C-Y master alloy suggests the best refining effect.The grain size of Al-Cu-Mn alloy was decreased from about 400?m to about 45?m when the alloy was refined by Al-Ti-B-C-Y master alloy.In addition the morphology of the grains changed from dendrite to equiaxed crystal.The Al-Cu-Mn alloy refined by Al-Ti-B-C-Y ribbons also shows the best mechanical properties.The combined action of microalloying element Cr and inoculants on Al-Cu-Mn alloy was also investigated in this paper.The results show that the addition of the Cr element can refine the grains of Al-Cu-Mn alloy slightly,but the grains are still dendritic morphology.The addition of Cr element make the refining effect of Al-Ti-B master alloy on Al-Cu-Mn alloy weak.But after adding a little amount of rare earth element Y the poisoning phenomenon of Cr disappeared and the grains of Al-Cu-Mn alloy were modified to fine isometric crystal.After adding Cr element the mechanical properties of Al-Cu-Mn alloy were improved.When the Cr element and Al-Ti-B-Y ribbons were added to the Al-Cu-Mn alloy at the same time the Al-Cu-Mn alloy achieve the best mechanical properties.Its ultimate tensile strength can reach to 520 MPa,its yield strength can reach to 420 MPa,the ductility can reach to 14.5%,and its hardness can reach to 185 HV.So it can be widely used in the industrial production.