Tool Wear Behavior in μ-turning of Nimonic 90 Under Vegetable Oil-Based Cutting Fluid

The characteristics such as high hardness and shear modulus, low thermal conductivity, strain hardening of Nickel-based superalloys lead to high machining forces and temperature, poor surface quality and integrity, rapid tool wear, etc. The present article investigates the tool wear mechanism of the tungsten carbide (WC) tool in µ-turning of Nimonic 90 under dry, wet, and vegetable oil-based cutting fluid (VCF). Canola oil is used as vegetable oil. Three different combinations of cutting speed, feed rate, and depth of cut are considered for analysis. The tool wear is characterized using optical and scanning electron microscopy. Machining with VCF shows an approximate reduction of flank wear width in the range of 12%-52% compared to dry and wet conditions. The main wear mechanisms observed on the tool flank and rake face are abrasion, built-up edge adhesion, and edge chipping. The VCF considerably reduces the adhesion and abrasion and, hence, increases tool life. The chips produced in dry conditions are found fractured and uneven, whereas, it had an uneven lamella structure in wet conditions. The VCF found reducing the plastic deformation in each cutting condition, as a result, producing fine lamella structured chips.

Influence of Tool Wear on Form Deviations in Dry Machining of UNS A97075 Alloy

Geometrical tolerances play a very important role in the functionality and assembly of parts made of light alloys for aeronautical applications. These parts are frequently machined in dry conditions. Under these conditions, the tool wear becomes one of the most important variables that influence geometrical tolerances. In this work, the influence of tool wear on roundness, straightness and cylindricity of dry-turned UNS A97075 alloy has been analyzed. The tool wear and form deviations evolution as a function of the cutting parameters and the cutting time has been assessed. In addition, the predominant tool wear mechanisms have been checked. The experimental results revealed that the indirect adhesion wear (BUL and BUE) was the main tool-wear mechanism, with the feed being the most influential cutting parameter. The combination of high feed and low cutting speed values resulted in the highest tool wear. The analyzed form deviations showed a general trend to increase with both cutting parameters. The tool wear and the form deviations tend to increase with the cutting time only within the intermediate range of feed tested. As the main novelty, a relationship between the cutting parameters, the cutting time (and, indirectly, the tool wear) and the analyzed form deviations has been found.

The Research of Tool Wear Mechanism for High-Speed Milling ADC12 Aluminum Alloy Considering the Cutting Force Effect

Tool wear is a major cause of accelerated tool failure during the milling of aluminum alloy. The periodically cutting force directly affect the cutting heat and tool wear due to the intermittent cutting characteristics of the milling process. The focus of this paper is to analyze the influence of the variation of cutting force on tool wear behavior. The change law of cutting force by cutting parameters was analyzed firstly. Secondly, the variation of the wear land width (VB) of tool flank face by the milling length was analyzed. Thirdly, the wear morphology and the energy dispersive spectrometer (EDS) results of tool rake face and flank face in different cutting parameters were observed by tungsten filament scanning electron microscope. Finally, considering the cutting force effect, the tool wear mechanism during high-speed milling of Aluminum-Alloy Die Castings 12 (ADC12, 12 means aluminum number 12) was analyzed. The cutting force in tangential direction is predominant during high-speed milling aluminum alloy, which decreases gradually with the increase of cutting speed but increases gradually with the feed rising. The adhesion-oxidation wear was main wear mechanism of tool rake face during high-speed milling. While adhesive wear was the main wear mechanism of the tool flank face during high-speed milling. It is found that the formation of adhesive wear is the process from particle adhesion to melting until the formation of adhesive layer, which related to the change of cutting force.

Machinability Investigation in Dry Turning of Ti–6Al–4V with a Novel TiB2–ZrC Cermet Tool Using RSM

To ensure accuracy and improve the processing efficiency of Ti–6Al–4V alloys, dry turning experiment of Ti–6Al–4V was carried out using a novel TiB2–ZrC cermet tool. The tool was reinforced by nanoscale VC additive and exhibited excellent hardness and fracture toughness. Response surface methodology (RSM) was used in the experiment to verify and evaluate the cutting performance of TiB2–ZrC cermet tool. The cutting forces and surface roughness (Ra) were selected as the optimization objective. Then the analysis of variance (ANOVA) was employed to ascertain the effective cutting parameters on response factors and demonstrate accuracy of the models. It was found that the effective cutting parameters on surface roughness was feed rate, while cutting depth significantly affected cutting forces. And the confirmation experiments showed that the predicted values coincide with experimental values nearly. Based on the optimized cutting parameters, the tool life and tool wear mechanism were investigated. When the vc, ap and f were 100 mm/min, 0.16 mm, 0.1 mm/rev, respectively, the cutting length and tool life could reach to 3233 m and 29.4 min, respectively, due to the excellent wear resistance and stability of TiB2–ZrC cermet tool at high cutting temperature. In this case, the main wear mechanism was adhesive wear and diffusion wear.