Modification of aluminium and aluminium alloys by AL-B master alloy

Abstract

Chemical compositions and microstructures affect on mechanical – physical and working properties of aluminium and aluminum alloys. Transition elements, such as Ti, V, Cr, Zr in solid solution greatly reduce the electrical conductivity of aluminium and its alloys. For reduction of detrimental effects of transition elements, Al-B master alloys are added into molten aluminium to occur reactions of boron and transition elements to form diborides of titanium, vanadium, chromium and zirconium, which are markedly insoluble in molten aluminium, then these transition elements have an insignificant effects on conductivity. In addition, Al-B master alloys is also used as a grain refiner of aluminium and aluminium alloys. Aluminium borides particles in Al-B master alloys act as substrates for heterogeneous nucleation of aluminium and its alloys. Al-B master alloys are prepared from low cost materials, such as boric acid H3BO3 and cryolite Na3AlF6, by simple melting method, easily realize in electrical wire and cable factories.