Friction and Wear Properties of Rapid Solidified H-Al-17Si Alloys Processed by UV Assisted Stir - Squeeze Casting with DLC-Star (CrN + a-c:H) Coating Under HFRR

Abstract

Tribological properties of rapid solidified hyper eutectic AlSi17Cu3. alloy were investigated under different loading conditions. The alloy was produced by the rheo-stir squeeze casting process with the T-6 condition. Experimental studies were conducted using high frequency linear reciprocating rig (HFRR) with a ball-on-plate geometry. The effect of applied load (10-50 N) on the wear and friction (COF) coefficients were studied under dry, lubricated (SAE15W40), and coated dry (DLC-Star) sliding conditions. For dry and lubricated sliding, COF values of hyper eutectic AlSi17Cu3.5-4Mg0.6-0.8 alloy were 0.26 and 0.042. A lower COF value of 0.013 was recorded with DLC-star (CrN + ac:H) coating under dry condition. Whereas, the least wear coefficient is also observed with DLC-star coating (4.6X10 -5 mm 3 /N.m) compared to the dry and lubricated sliding conditions (2.7X10 -3 mm 3 /N.m and 3.8X10 -4 mm 3 /N.m). The developments in COF and wear coefficients were mainly attributed to the distribution and size of primary Si granules and the formation of transfer layers on the coated surfaces of AlSi17Cu3.5-4Mg0.6-0.8 alloy. Surface morphologies were examined using SEM, AFM, surface roughness profilometer, and advanced metallurgical microscope (AMM) analysis techniques.

Wear studies on Al-Si automotive alloy under dry, fresh and used engine oil sliding environments

“…A decrease in frictional force can be attributed to better hardness and strength, as the low plastic deformation of the alloy at real contact areas may lead to a lack of friction coefficient [45]. It is also due to the creation of an intermediate oxide-rich layer between mating surfaces which acts as a solid lubricant [46]. At the initial stage, the friction coefficient of the sample increases to a peak value, followed by a gradual steady-state value.…”

Effect of Load on Tribological Characteristics of H-AlSi24Cu3.8Mg0.8 Alloy Under Dry, Lubricated, and Coated (a–c: H) Sliding Conditions

“…E-MRS spring meeting was from June 2 to 5 in Strasbourg, France [37]. Te development of the alloys from ancient to present time initiated from accidents to through the use of well-defned scientifc principles [38]. A DLC coating has been shown in these investigations to have exceptional hard flm properties for fghting coefcients of friction and wear rates in several tribological applications.…”