Achieving the Minimum Roughness of Laser Milled Micro-Impressions on Ti 6Al 4V, Inconel 718, and Duralumin

Abstract

Titanium-aluminium-vanadium (Ti 6Al 4V) alloys, nickel alloys (Inconel 718), and duraluminum alloys (AA 2000 series) are widely used materials in numerous engineering applications wherein machined features are required to having good surface finish. In this research, micro-impressions of 12 µm depth are milled on these materials though laser milling. Response surface methodology based design of experiment is followed resulting in 54 experiments per work material. Five laser parameters are considered naming lamp current intensity (I), pulse frequency (f), scanning speed (V), layer thickness (LT), and track displacement (TD). Process performance is evaluated and compared in terms of surface roughness through several statistical and microscopic analysis. The significance, strength, and direction of each of the five laser parametric effects are deeply investigated for the said alloys. Optimized laser parameters are proposed to achieve minimum surface roughness. For the optimized combination of laser parameters to achieve minimum surface roughness (Ra) in the titanium alloy, the said alloy consists of I = 85%, f = 20 kHz, V = 250 mm/s, TD = 11 µm, and LT = 3 µm. Similarly, optimized parameters for nickel alloy are as follows: I = 85%, f = 20 kHz, V = 256 mm/s, TD = 8 µm, and LT = 1 µm. Minimum roughness (Ra) on the surface of aluminum alloys can be achieved under the following optimized parameters: I = 75%, f = 20 kHz, V = 200 mm/s, TD = 12 µm, and LT = 3 µm. Micro-impressions produced under optimized parameters have surface roughness of 0.56 µm, 2.46 µm, and 0.54 µm on titanium alloy, nickel alloy, and duralumin, respectively. Some engineering applications need to have high surface roughness (e.g., in case of biomedical implants) or some desired level of roughness. Therefore, validated statistical models are presented to estimate the desired level of roughness against any laser parametric settings.

Machining of Inserts with PCD Cutting-Edge Technology and Determination of Optimum Machining Conditions Based on Roundness Deviation and Chip-Cross Section of AW 5083 AL-Alloy Verified with Grey Relation Analysis

“…However, many publications consist of an analysis of only one type of PCD machining such as grinding, EDM or LASER. The machining of innovative materials based on titanium and aluminum lightweight alloys for the aerospace and automotive industries is of great importance [26].…”

Machinability of AA 2024 aluminum alloy by fiber laser engraving process

“…Additionally, if the metallic components are complicated to machine using conventional machining methods, tool-related problems affect the surface quality and dimensional accuracy, weakening those properties [7]. Advanced machining techniques, namely electro-discharge machining, wire electro-discharge machining, abrasive water jet, ultrasonic machining, plasma beam machining, and laser beam assisted machining techniques, could provide many advantages in precision manufacturing of small parts with intricate details at desired dimensional accuracy and surface tolerances [8][9][10][11][12][13]. The micro-sized components exhibit various applications in industries, e. g., medicine, semiconductor, and aerospace.…”

“…A computer-controlled laser beam could be used as a thermal tool to process the desired profile on the metal surface [13]. The small diameter of the laser beam enables particularly successful engraving and milling applications, e. g., micro-product, micro-texture, micro-perforated microfluidic field, micro-channel, micro-valves and pumps [10,12,13]. Laser beam-assisted applications could be applied to all materials regardless of their hardness, especially to materials that are difficult to cut using a cutting tool [12,14].…”

“…The small diameter of the laser beam enables particularly successful engraving and milling applications, e. g., micro-product, micro-texture, micro-perforated microfluidic field, micro-channel, micro-valves and pumps [10,12,13]. Laser beam-assisted applications could be applied to all materials regardless of their hardness, especially to materials that are difficult to cut using a cutting tool [12,14]. This study used AA 2024-T351 aluminum alloy, duralumin, for laser beam-assisted engraving applications.…”

“…It is used in the transport industry for hardware parts and the aircraft industry for precision fittings and structural components (wing and fuselage parts under tension); it is worth noting that precisely machined materials exhibiting high strength-to-weight ratio, hardness, and fatigue strength are required in those industries [15,16]. Some difficulties could be occurred in the machining process of AA 2024 aluminum because of the chip formation-based problems [12,[17][18][19]. Build-up edge formation changes the tool rake angle, affecting the chip morphology and deteriorating the machined surface quality [17].…”