Electron-ion-plasma alloying of silumin with titanium
Aluminum alloys, primarily silumins, have found wide application in aircraft, automobile, and motor industries. The use of silumins as structural materials is governed by their excellent castability, high mechanical strength and corrosion resistance, and relatively small specific weight. It is due to these properties that silumins rank among candidate materials to replace stainless steel in various constructions. An obvious shortcoming of silumins is their low strength characteristics which considerably narrows the application range of these materials [1, 2]. Recently technology development of the hardening of silumins associated with the development of combined processes including sequentially several ways to modify the material [3]. Electro-explosive alloying and pulsed electron beam treatment are widely used in industries for surface modification [1-4]. The first one leads to alloying of surface layer of thickness up to ~ 100 μm but exhibits the rough surface. Another one modifies a thin layer but has an ability to smooth the surface. The aim of the work was to combine these two types of treatment to obtain a thick alloyed layer with smooth surface. Moreover we compared this method of surface modification with combined treatment including vacuum arc deposition a Ti coating followed by electron-beam. The structure and phase composition of the silumin before and after treatment by electron beam were investigated by scanning electron microscopy (SEM - 515 “Philips”) and transmission electron microscope (EM-125). The elemental composition of the samples was studied by scanning electron microscope SEM-515 “Philips” with EDAX microanalyzer Genesis. The microhardness measurements were carried out using the PMT-3 microhardness tester at normal load of 0.5 N. The modes of treatment leading to a dramatic improvement of microhardness and wear-resistance of modified material have been determined.