Microstructure, Hardness, and Linear Reciprocating Sliding Wear Response of Directionally Solidified Al–(2.5, 3.5, 4.5)Cu–(0.25, 0.50)Cr Alloys

Aluminum alloys containing transition metal alloying elements have attracted interest from researchers. The effect of Cr additions 0.25 and 0.50% on the thermal profile, microstructure, hardness, linear reciprocating sliding wear response as-cast hypoeutectic Al–Cu with 2.5, 3.5, 4.5% Cu (wt.%) was investigated. binary ternary Al–Cu–Cr were directionally solidified under upward non-steady state heat transfer conditions using a dedicated solidification apparatus. Thermal analysis based differential (DTA) cooling curve profiles performed to determine parameters such as Liquidus temperature (TL), transformation enthalpy (ΔH), liquid rate (ṪL). Samples extracted ingots submitted optical microscopy, hardness measurement, test high-frequency rig (HFRR). results showed decrease at beginning (TL) (ΔH) when both alloy contents increased, higher influence Cu. addition decreased rates, whereas increase in concentration an opposite behavior, increasing rates. refinement primary dendrite arm spacing (λ1), consequence enhanced alloys, maximum value 58 HB achieved Al–4.5Cu–0.50Cr alloy. tests indicated better associated microstructure for 2.5% Cu, contents, almost constant behavior 3.5% performance that resistance coarsening λ1 amount eutectic microconstituent.