Aluminium alloy 8011 matrix composites reinforced with different weight percentages of ZrB2 were successfully fabricated using an in-situ casting technique. X-ray diffraction and scanning electron microscopic analyses were performed to examine the presence and distribution of the reinforcements in the composites. Wear tests were performed with the weight percentage of the reinforcement, temperature, load, sliding velocity and sliding distance as the input parameters for the wear rate as response. D3 steel was used as the counterpart. The effects of various factors on the wear rate were analysed using analysis of variances. The optimal combination of the 1500-m sliding distance, 4 % of mass fractions of ZrB2 reinforcement, 200°C temperature, 10 N load and 2 m/s sliding velocity was found to give the minimum wear rate. Keywords: in-situ stir casting, aluminium-matrix composites, wear behavior, design of experiments V~lanku avtorji opisujejo uspe{no izdelavo kompozitov z matrico iz Al zlitine 8011 in oja~ano z razli~no vsebnostjo ZrB2. S pomo~jo spektroskopije uklona rentgenskih`arkov (XRD) in vrsti~ne elektronske mikroskopije (SEM) so dolo~ili dele`in porazdelitev oja~itvene faze v izdelanih kompozitih. Izvedli so tudi teste njihove obrabe v odvisnosti od temperature, obremenitve, hitrosti in razdalje drsenja. Kot protidrsni element so uporabili orodno jeklo D3. Z analizo varianc so dolo~ili vpliv razli~nih faktorjev na hitrost obrabe. Ugotovili so, da je dose`ena najmanj{a hitrost obrabe, ko so razdalja drsenja 1500 m, masni dele`ZrB2 4 %, temperatura 200°C, obremenitev 10 N in hitrost drsenja 2 m/s. Klju~ne besede: in-situ litje s preme{avanjem taline, kompoziti z matrico na osnovi Al zlitine, obstojnost proti obrabi, na~rtovanje eksperimentov

In-situ aluminium alloy 8011 matrix composites containing different weight percentages of titanium diboride were synthesized by flux assisted synthesis using stir casting technique. The metallurgy of the in-situ AA8011-TiB2 composites was analyzed using X-ray diffractometer, scanning electron microscope and energy dispersive spectroscope to disseminate the formation and distribution of reinforcements. Density, microhardness and tensile strength of cast AA8011 and in-situ AA8011-TiB2 composites were measured and analyzed. The in-situ formed TiB2 reinforcements showed the maximum hardness of 55.03 Hv and the maximum tensile strength of 158.2 MPa for 8 wt. % of TiB2 whereas the percentage elongation of 7.2% is observed at 4 wt. % of TiB2. Further, the fractography analysis performed on the fractured tensile samples and the mechanism of failures were identified and reported.