Machining characterization and optimization under different cooling/lubrication conditions of Al-4Gr hybrid composites fabricated by vacuum sintering. (February 2023)

• Record Type: Journal Article
• Authors: Değirmenci, Ünal; Usca, Üsame Ali; Şap, Serhat
• Is Part Of: Vacuum. Volume 208(2023)
• Publication Date: 2023-02
• Subjects: Al-4Gr hybrid composites -- CNC milling -- Cryo-LN2 -- MQL -- Machinability performance; Vacuum -- Periodicals; 621.55
• DOI: 10.1016/j.vacuum.2022.111741
• Languages: English
• ISSNs: 0042-207X

Abstract

Abstract: In this study, the effects of different cooling/lubrication strategies and cutting parameters during milling hybrid composites based on Al-4Gr, a new material, were investigated. The main matrix was formed by adding Gr at a constant rate (4%) to Al. Hybrid composites were fabricated by vacuum sintering by adding WC and Al2 O3 in different ratios (2-4-8 wt.%). Environmentally friendly cryogenic liquid nitrogen (cryo-LN2 ) and minimum quantity lubrication (MQL) fluids were used as cooling and lubricating environment in the milling process. Three different cutting speeds (150, 225, 300 m/min), three different feed rates (0.150, 0.225, 0.300 mm/rev) and a single depth of cut (0.5 mm) were selected for milling. Surface roughness, flank wear, cutting temperature, and chip morphology were evaluated for different cooling/lubrication environments. As a result, the cryo-LN2 environment reduced the surface roughness, flank wear, and cutting temperature by 34.9%, 18.5%, and 69.5%, respectively, compared to the dry medium. Adhesion wear was reduced in MQL and cryo-LN2 environments. In addition, it was determined by the analysis of variance that the most effective factor among the response parameters was cooling/lubrication. The cooling/lubrication environment has an effect of 74%, 58%, and 94% on surface roughness, flank wear, and cutting temperature, respectively. Highlights: Novel Al-4Gr hybrid composites were milled in dry, MQL, and cryo-LN2 environments. Surface roughness, flank wear and cutting temperature results were evaluated in terms of cutting environments and parameters. According to the Al-4Gr hybrid composite type, the most effective processing environment is cryo-LN2 . Experimental results analyzed with the help of ANOVA, and the most effective parameters were determined.