Micro milling mechanism and tool wear of Unidirectional HfZrTiTaNbCu0.2 fiber reinforced aluminum matrix composites

This study delves into the micro milling and tool wear mechanisms of 2A97 aluminum matrix composites reinforced with HfZrTiTaNbCu0.2 fibers. Finite element analysis models the fibers as uniformly distributed cylindrical entities within the matrix, applying various material constitutive laws, failure, and evolution criteria to simulate milling at three specific angles (45 degrees, 90 degrees, 135 degrees). The research examines the effects of milling parameters, fiber orientations, and tool coating thickness on cutting forces, temperatures, surface roughness, and tool wear. Key findings include: These forces escalate with both cutting speed and depth of cut. Notably, at a feed rate of 68 mu m/z, the cutting force is 1.5 times higher compared to 58 mu m/z.An increase in milling parameters leads to higher cutting temperatures. Differences of 12 degrees C and 10 degrees C were noted at varying depths of cut (10-25 mu m) and cutting speeds (1000-1200 mm/s), respectively. As the fiber angle increases, cutting forces first decrease and then rise, with fibers oriented at 90 degrees experiencing only 53 % of the force compared to those at 135 degrees. Similarly, cutting temperatures follow this trend, with a 26 degrees C difference between 45 degrees and 90 degrees fibers. This factor is positively correlated with depth of cut and fiber angle. Surface roughness at a 55 mu m depth is 4.3 times that at 10 mu m, and 135 degrees fibers show 2.7 times the roughness of 45 degrees fibers. However, within feed rates of 48-58 mu m/z and cutting speeds of 800-1200 mm/s, there is a notable decrease in surface roughness. Variations in cutting parameters, fiber orientations, and tool coating thickness significantly influence peak tool stress. Stress concentration at the central groove tends to reduce tool wear, whereas stress concentration at the peripheral edge or strain concentration at the bottom edge exacerbates it.