China
Africa
Explore chapters and articles related to this topic
Recent Trends of Cutting Fluids and Lubrication Techniques in Machining
Published in Yashvir Singh, Nishant K. Singh, Mangey Ram, Advanced Manufacturing Processes, 2023
Cutting fluid performs microcapillary action in the machining zone to provide sufficient lubrication, acts as a heat-carrying medium, and also helps in chip evacuation [7]. Cutting fluids are generally used for difficult-to-machine materials and in complex machining. Metalworking processes are intended to have tool-work contact [8]. In order to separate them, a boundary of lubricant needs to be placed in between. The problem of friction and tool wear is addressed by the lubricating capability of the cutting fluid while the cooling action encounters high temperatures. The various factors such as cutting conditions, cutting environment, cutting tool, machine tool chatter, and workpiece nature significantly influence machining performance. The cutting fluid, its thermo-fluidic properties, method of application, its flow rate/pressure, along with quantity, is, in turn, directly linked with the machining performance. The factors that control the machining performance are shown in Figure 1.1.
Investigation on Dynamical Prediction of Tool Wear Based on Machine Vision and Support Vector Machine
Published in Wasim Ahmed Khan, Ghulam Abbas, Khalid Rahman, Ghulam Hussain, Cedric Aimal Edwin, Functional Reverse Engineering of Machine Tools, 2019
Tool wear investigations in machining have been amongst the important research areas during the last several decades as the quality of the machined product largely depends on the tool wear. Tool wear is defined as the change in the tool shape from its original shape during cutting in machining process. If the machining process continues with a worn tool, the dimensional accuracy, surface quality of finished component, and even process stability will be deteriorated. Therefore, the prediction of tool wear in machining process is very meaningful in order to improve machining quality and increase productivity. For actual machining system, the estimated tool wear can be used to optimize tool replacement and compensate machining error induced by tool wear. Thus, the tool wear estimation becomes crucial in machining processes.
Light alloys and their machinability
Published in Diego Carou, J. Paulo Davim, Machining of Light Alloys, 2018
Mohd Danish, Turnad Lenggo Ginta, Muhammad Yasir, Ahmad Majdi Abdul Rani
For machining titanium at high cutting speeds, uncoated cemented carbide cutting tools are normally preferred (Jawaid, Che-Haron, and Abdullah 1999). During cutting, severe chipping and flaking of the cutting edge occur during milling of titanium alloys with carbide tools. These types of failures are due to the high thermomechanical and cyclic stresses, adhesion, and tool face wear of the workpiece material (Jawaid, Sharif, and Koksal 2000). Moreover, machining at a high cutting speed tends to increase the temperature at the cutting zone, especially at the edge of the tool, which results in excessive stresses at the tool nose, producing plastic deformation and tool wear (Che-Haron and Jawaid 2005). Sintered carbide tools are used in the machining of titanium alloys when the conventional speeds range from 30 to 100 m/min, resulting in low productivity (Su et al. 2006). The reactivity of titanium alloys is very high with the tool materials especially at a higher (about 500°C) cutting temperature. Titanium atoms diffuse into the carbide cutting tool, which leads to a chemical reaction with carbon and forms a layer of titanium carbide (TiC) at this temperature. This chemical interaction is insignificant between carbide and titanium alloys at low cutting speeds. At low cutting speeds, tool wear is basically caused by thermal fatigue, mechanical fatigue, and microfractures. Tool particles are plucked off from those microcracks, which are sandwiched between the tool and the workpiece, giving rise to abrasion wear.
A new study for prediction and optimisation of energy consumption during high-speed milling
Published in International Journal of Computer Integrated Manufacturing, 2022
Tool wear and damage are demonstrated on the cutting edge in one or several types or forms (Martínez-Arellano, Terrazas, and Ratchev 2019; Shen et al. 2015). During milling, HSM tool wears types generally include the flank, notch, crater, plastic deformation and nose wear types. Each of these types of wear is associated with a wear mechanism or cause of appearance. Among these types of tool wear, flank and crater wear are the most important measured forms of tool wear (Zhou et al. 2020). Flank wear is most commonly used for wear monitoring because it is easily measured (Siddhpura and Paurobally 2012). Therefore, in recent years, researchers have often used flank wear as the main indicator of tool wear (Lu et al. 2017; Yu et al. 2018). Figure 6 illustrates the effect of tool wear on HSM with the flank wear (VB) of the milling cutter. The filtering algorithm is based on Bayesian particle theory (Dong et al. 2005; Li et al. 2021) which has been widely used to solve nonlinear filtering problems and is used to estimate the cutting edge geometrical trajectory considering STW (Zaretalab et al. 2018). Let R and R’VB be the radius of the original and when worn blades, respectively. In triangle ΔVAB, distance VA is determined by the following equation:
Experimental investigation on friction formation during slot milling of Nimonic263
Published in Materials and Manufacturing Processes, 2021
Sivalingam Gowthaman, Timmaiah Jagadeesha
Where γ, φ andrepresents the radial rake angle, helix angle and chip flow angle (comparable to helix angle), respectively. Moreover, the measured Friction and Normal Pressure Coefficients (FPC and NPC) are the direct indications to compute the friction (Fn) and normal force (Ff) (resolved forces over the rake face) in the direction of rake face. Compared to friction and normal force, the major source for the cause of tool wear is the friction force in relation to the normal force, due to the existence of severe adhesion phenomenon. The friction and normal forces are computed as follows (eq. 4).[11]
Dry turning performance of TiN–WSx/TiN hard-lubricious bilayer composite coating
Published in Machining Science and Technology, 2020
Tushar Banerjee, A. K. Chattopadhyay
Machining without hazardous cutting fluids, commonly known as dry machining, is receiving immense attention worldwide owing to its environment friendliness. It has been estimated that costs associated with procurement, usage, maintenance and post-treatment of liquid lubricants constitute around 7–17% of the total manufacturing cost, which overshadow the tooling cost of approximately 2–4% (Klocke and Eisenblatter, 1997). Usage of cutting fluids also poses considerable threats to operator’s health owing to generation of mist and aerosols during the machining process (Sutherland et al., 2000). However, cutting fluids provide cooling and lubricating action in the machining zone, which results in lower cutting forces, reduced tool wear rate and improved surface finish of workpiece. Presence of cutting fluid also permits to increase cutting velocity, which directly increases productivity. Hence, suitable alternative(s) must be developed before eliminating or reducing the use of such cutting fluids in machining process and one such method is to employ coated cutting tools with built-in solid lubricating provision (Klocke and Eisenblatter, 1997; Weinert et al., 2004).