Micro-nano Structure Of In Situ Aluminum Based Composite Inoculant And Its Modifying And Refining In Aluminum Alloys

Owing to light density and high strength,traditional aluminum was the preference for lightweight structural and widely used in the field of military aerospace and civil construction.With the development of science and technology society,outstanding scientists made deeper explorations on the research and development of aluminum,hoping to develop the comprehensive performance materials.Among the many measures,inoculation and refinement was a high international research,which is commonly used and improve the performance of aluminum alloys.In addition,adding a refiner is environmentally friendly and conveniently.In this work,an inoculant containing different sub-micron ceramic particles was prepared by in-situ synthesis,and its refinement effect and mechanism were systematically elucidated.In this article,aluminum powder,titanium powder,B₄C,and graphene was mixed by ball milling and then prepared ignot mainly containing Ti B₂ and Ti C with different sizes after pressing and sintering.Ribbons were carried out by melt spinning,which are beneficial to Al-Si alloys and play the greatest role in the refinement process.The mean grain size of Al-Si alloys was reduced from 750?m to 120?m after adding 0.6 wt.%ribbons.In addition,the modification of Sr makes the Si phase present a network,and the morphology of the Si phase modifying obviously after T6 treatment,which is from needle-like to fine granular-like.Finally,because the microscopic evolution of Ti C and Ti B₂ particles in Al and the existence of good interfacial bonding,the tensile strength,yield strength,elongation and Vickers hardness of Al-Si reaching 302 MPa,270 MPa,7.6%,and 119.6 HV,respectively.It is showed that Ti C-Ti B₂/Al inoculant prepared by graphene is a feasible inoculant for Al-Si alloys.Al N-Ti N/Al composite inoculants with?500 nm were compared by arc-melting and rapid solidification and diffreent phases was shown in the XRD spectrum,which were Ti N,Al N and Al₃Ti.The composition of the ceramic phases were observed and their existence will reduce the grain size to a certain extent.Interestingly,a small amount of Si in Al matrix,which could enhance the solid-solution strengthen.In addition,ultrasonic cavitation has a significant effect on improving the properties of aluminum.Only with 0.4 wt.%additions,a series of physical changes will occur in the aluminum melt to achieve the most satisfactory effect,when the frequency is 21871 Hz.The mean grain size of pure aluminum was reduced from 760?m to 140?m,respectively.Meanwhile,mechanical properties of pure aluminum was increasing with a tensile strength of 142.1 MPa and a hardness of 109.3 HV.It is suggested that ultrasonic cavitation and the inoculation of multiphase nano-sized ceramic particles was effective measures to refine pure aluminum.