Milling parameters of Al-Cu and Al-Si cast alloys

Abstract

The present study was carried out to study the machinability i.e. milling characteristics of an Al-6%Cu-0.7%Si alloy (in the as-cast, T5 and T7 aging conditions) and compare these characteristics to those of well-defined B319.0 (as-cast, T7-treated) and A356.0 (as-cast, T6-treated) alloys. Wet milling was carried out on 15 blocks prepared from each alloy using new carbide inserts for about 120m machining distance. Thirty-five blocks (12 in x 7 in x 1.5 in) were employed. The milling was carried out using a CNC Huron KX Five 5axis high speed machine. The experiment comprised the CNC machine, the blocks to be machined, a table dynamometer with piezoelectric sensors that are responsible for detecting and measuring the cutting forces, a signal amplifier and an A/D converting unit. New and dull cutting inserts were used for each alloy group. Thirteen layers of material were removed from each block, where each layer consisted of 10 paths, and the depth of cut was 1.35 mm. The results employing new inserts showed that the cutting forces for Al-Cu based alloys were not affected by the applied heat treatment. The presence of Cu in the B319.0 alloy neutralized to some extent the harmful effect of the hard Si particles. Maximum cutting forces were obtained from machining the T6-treated A356.0 alloy, due to the presence of a high density of hard eutectic silicon particles (approximately 41495 particles∕mm 2) in addition to a dense precipitation of ultra-fine Mg 2 Si particles. Thus, the 6% Cu in the Al-Cu based alloy may be considered to act as a self-lubricant, leading to much smoother finishing surfaces compared to those exhibited by B319.0 and A356.0 alloys. Similar observations were reported on the wearing of the drilling tools. In addition, after covering 120m machining distance, tiny burrs were found adhered to the outer edges of the block workpiece, whereas the burr in the case of A356.0 alloy was separated from the block.

Role of Li and Sc Additions and Machining Conditions on Cutting Forces on Milling Behavior of A7075-Based Alloys

“…The machinability of a certain material is evaluated based on one or more of the following factors: (a) tool life, (b) cutting forces, (c) chip formation, and (d) the quality of the machined surface. In the following sections, the machinability of aluminum alloys is explained by referring to the above-mentioned machinability criteria [67]. According to Songmene et al [68], burrs forming during machining are defined as an extension of the material beyond the workpiece edges.…”

Towards Smart Additive Manufacturing: Cost and Component Complexity

“…The ability to print different metallic materials into functional, usable parts is very important for making these technologies tangible and so they can potentially work as a replacement for conventional processes, or at least supplement and improve those processes [1][2][3][4]. Potential benefits of AM may include: (1) producing complex and customized parts that cannot be produced by conventional machining [5,6], (2) reduce joining/ assembly processes [6], (3) reduced material wastage [5,7], reduce energy consumption from life cycle perspective [8][9][10][11][12][13], (4) reducing component lead time and life cycle cost [6,14,15], reducing spare part inventories [6,16], to name a few. Studies indicate that additive manufacturing technology is only suitable for low production volumes because of the high cost of materials and machines; however, in some cases, AM can replace conventional (subtractive) manufacturing.…”