Investigation on the behaviour of the functionaly gradient material consisting of boron carbide and aluminum alloy

Abstract

In the current study the effect of different temperatures on the aging behaviour of a functionally gradient material was investigated to observe the variation of hardness with respect to the aging time. To do this, the functionally-gradient-material (FGM) specimens, containing boron carbide and aluminum alloy, were produced with hot pressing. Three different layers were used in the FGM samples. Then the macro and micro examinations were carried out to observe the interface between the layers, the porosity, the grain size and probable cracks in these samples. After that the specimens were solutionized at 470 degrees C for I h. Next, the artificial aging at 100 degrees C, 120 degrees C and 150 degrees C was applied to the FGM specimens for 96 h. During the aging treatment, the Brinell hardness measurements were made on the samples at certain intervals. Moreover, three-point bending tests were also carried out to clarify the influence of the aging treatment on the strength of the FGM. Experimental results indicated that the highest hardness values were obtained at 120 degrees C after the aging period of 48-65 h. The aged specimens exhibited higher bending strength than the solutionized specimens.

V tej {tudiji je prikazan vpliv razli~nih temperatur na staranje funkcionalnega gradientnega materiala in spreminjanje trdote v odvisnosti od ~asa staranja. Vzorci funkcionalno gradientnih materialov (FGM), ki vsebujejo borov karbid in aluminijevo zlitino, so bili izdelani s stiskanjem v vro~em. Trije razli~ni sloji so bili uporabljeni za FGM-vzorce. Na vzorcih so bile izvr{ene makro- in mikropreiskave stikov med sloji, dolo~ene so bile poroznost, velikost zrn in prisotnost morebitnih razpok. Potem so bili vzorci 1 h raztopno `arjeni na 470 °C, nato pa umetno starani 96 h na temperaturah 100 °C, 120 °C in 150 °C. Med postopkom staranja so bile v dolo~enih intervalih izvr{ene meritve trdote po Brinellu. Dodatno je bil izvr{en {e trito~kovni upogibni preizkus, da bi opredelili vpliv staranja na trdnost FGM. Rezultati preizkusov ka`ejo, da je bila dose`ena najvi{ja trdnost pri staranju med 48 h in 65 h na temperaturi 120 °C. Starani vzorci so pokazali ve~jo upogibno trdnost kot raztopno `arjeni vzorci