Measurement and Analysis of Tool Wear Using Vision System

In this experimental work dry turning process carried out on EN47 spring steel with coated tungsten carbide tool insert with 0.8 mm nose radius are optimized by using statistical technique. Experiments were conducted at three different cutting speeds (625, 796 and 1250 rpm) with three different feed rates (0.046, 0.062 and 0.093 mm/rev) and depth of cuts (0.2, 0.3 and 0.4 mm). Experiments are conducted based on full factorial design (FFD) 33 three factors and three levels. Analysis of variance is used to identify significant factor for each output response. The result reveals that feed rate is the most significant factor influencing on cutting force followed by depth of cut and cutting speed having less significance. Optimum machining condition for cutting force obtained from the statistical technique. Tool wear measurements are performed with optimum condition of Vc = 796 rpm, ap = 0.2 mm, f = 0.046 mm/rev. The minimum tool wear observed as 0.086 mm with 5 min machining. Analysis of tool wear was done by confocal microscope it was observed that tool wear increases with increasing cutting time.

A novel approach of combined edge detection and segmentation for tool wear measurement in machining

Cryogenic-based machining has been drawing attention for machining hard metals and super alloys such as the titanium alloys due to environmental concerns and growing regulations over pollution. In this study, cryogenic-assisted milling of Ti–6Al–4V has been performed with the preheated workpiece methods to avoid the cryogenic hardening by liquid nitrogen (LN2). Preliminary experiments show an increase in the cutting force due to cooling of the workpiece; therefore, workpiece preheating was adopted to increase the workpiece temperature. Three cutting speeds and three machining environments (dry, cryogenic, and cryogenic plus preheated) were considered in the analysis of tool wear, cutting forces, tool wear morphology, and chip morphology. Soft (Si coating) and hard (CrTiAlN)-coated tools were used in this study. It was observed that the tool life was increased by 50 to 90 % for Si-coated tools and 50 to 55 % for CrTiAlN-coated tools. The tool wear morphology showed that rubbing and chipping were the primary tool wear mechanisms. It is expected that the present work will be useful for improving tool life and reducing the cost of hard metal products. It may also be useful for reducing the ecological problems by conventional cutting fluids.

Titanium is a material that has a good strength to weight ratio, excellent corrosion resistance, and resistant to high or low temperatures Titanium alloys that are used in various industrial fields, one of them is the Ti6Al4V alloy. Micro drilling has a high rotational speed which results in tool wear, high temperatures, and surface roughness. This research uses The Finite Element Method (FEM) simulation. The application used is DEFORM 3D based on parameters from previous studies. The purpose of this research is to identify the progress of tool wear in a simulated manner on the Ti6Al4V alloy micro-dilling and analyze the tool wear on the Ti6Al4V alloy micro-drilling under dry machining conditions. Machining trials used CNC micro-drilling at various of cutting parameters such as cutting speed of 10.000 and 15.000 rpm. The results showed that the tool wear progress at the 5th hole was 0.00346 mm, the tool wear progress at the 10th hole was 0.00462 mm and the tool wear progress at the 15th hole was 0.00525 mm. Analyzing tool wear in simulated machining and experimental machining in dry conditions has a high wear value. Tool wear is simulated by measuring the radius of the tool in the 15th hole valued at 0.09973 mm. Tool wear is experimentally measured from the tool radius in the 15th hole valued at 0.0101 mm. The tool mesh is changed due to the tool wear. The tool mesh in the 5th hole is worth 17372 mesh. The tool mesh in the 10th hole is 15662 mesh. The tool mesh in the 15th hole was highly reduced by 13021 mesh. Tool wear affects the change in tool mesh. With increasing tool wear then tool mesh is reduced. The next cause of tool wear is the tool temperature in the machining process.

The machining of hard particle reinforced metal matrix composite material is always challenging. The machining behaviour of aluminium-based metal matrix composites (Al-MMCs) can be entirely different from conventional materials. This paper presents an experimental study of the effect of cutting parameters like cutting speed on surface quality and tool wear. Even the matrix material can be ductile, but hard particles and their binding with matrix material can bring a difference in the machinability of composite materials, specially MMCs. Three different MMC compositions, i.e. MMC reinforced with 15%, 20% and 25% SiC, were machined at various cutting speeds and feed rates. Tool wear and surface roughness of the machined surface of MMC were examined. Increased content of SiC increases the mechanical properties like hardness and compressive strength but was found detrimental to tool and surface quality. Tool wear was found increasing with both increasing feed rate and cutting speed. Application of image processing for measurement and prediction of tool wear is attempted by capturing the images of tool insert and processing using a MATLAB® based algorithm. Results are in line with many other research and establish the scope of future work for non-contact measurement of tool wear in real-time.

In drilling Carbon-Fibre-Reinforced Polymers (CFRP)/Al stacks, adaptive drilling facilitates the optimisation of cutting parameters for each constituent stack layer and tool wear, thus enhancing cutting efficiency and borehole quality. This study proposed a knot–Temporal Pyramid Pooling (TPP) model aimed at monitoring both process incidences and tool wear in the drilling of hybrid stacks, which subsequently informs the machine tool to adjust cutting parameters or, if necessary, replaces the tool. TPP is introduced to remove the restriction of input dimensions, allowing for the acceptance of inputs with arbitrary shapes. On the other hand, a knot structure has been proposed to incorporate the classification of process incidences into the tool wear analysis, thereby enhancing prediction accuracy. The proposed model achieves a process incidence identification accuracy of 99.19% and a Mean Absolute Error (MAE) of 10 μm in tool wear prediction, demonstrating robust performance across a wide range of sampling conditions. This achievement facilitates decision-making and optimisation relating to cutting parameters and tool replacement in the context of adaptive drilling of aerospace materials.

A review of tool wear estimation using theoretical analysis and numerical simulation technologies

Comprehensive analysis of material removal rate, tool wear and surface roughness in electrical discharge turning of L2 tool steel

This article deals with the comparative wear of CNMG-coated sintered carbide indexable cutting inserts by several manufacturers when turning 1.6582 steel hardened to 40–44 HRC. The main goal will be to demonstrate the different course of wear by testing seemingly identical inserts for engineering companies, showing the connection between the course of wear and the production of waste in the form of chips. The monitored type of wear was the flank wear VBmax of a cutting tool depending on the length of the machining time. Additionally, the effect of cutting tool wear on chip production, i.e., their quantity, shape and size, was monitored. For the purpose of mutual comparison, uniform cutting conditions were chosen on the basis of previous experiments, ensuring the stability of the given cutting process. For flank wear analysis, optical and electron microscopes were used. Meanwhile, a portable roughness tester was used to analyze the roughness of the machined surface. It was found that the quality of the interconnected coating layers has a perceptible influence on wear rate of the evaluated cutting inserts. The relation between the degree and characteristics of wear on the one hand, and the properties of the produced chips that identify the effect of the difference in the deposition layers using EDX/SEM analysis on the other, foreshadows the importance of choose between products with similarly declared properties was found. The current assessment of cutting tool wear and the evaluation of the chip produced has significant economic potential for manufacturing companies seeking to minimize costs.

The nickel superalloy VAT 32 was developed as substitute of UNS N07751 alloy in manufacturing of automotive internal combustion valves of high performance. The formation of niobium carbides gives to VAT 32 superalloy a high wear resistance, desirable for application in automotive valves. This creates, however, a higher difficulty in machining this material. This paper studied the turning of VAT 32 with Ti-Al-Si-N coated carbide tool by the physical vapor deposition (PVD) process. The analyses of tool wear, surface quality and cutting power were made. The analyses were made using a Taguchi’s method of design of experiments, through L8 orthogonal array. The factors evaluated were cutting speed, feed rate, depth of cut and lubrication condition, dry machining and using abundant lubrication. The influence of the cutting parameters in the analyzed responses were found by analysis of variance (ANOVA) and the optimized set for minimum variability of the process was found by S/N ratio values analyses.

Due to its good mechanical properties, the Compacted (Vermicular) graphite cast iron (CGI) has found a lot of applications in the automobilistic field. One of the applications is the production of high power diesel engine blocks that, due to the higher strength compared to the usual gray cast iron, allows the increase of the pressure inside the cylinder and, consequently, production of high level of energy. The result is the better fuel burning what decreases the fuel consumption and the pollutants' emission levels. However, when CGI replaces gray cast iron, the machining processes used to produce the components are more difficult, with lower tool lives and higher power consumption. Moreover, because usually the raw material to produce cast products of CGI is selected from scrap, some residual level of titanium is present. Thus, the goal of this work is to study the influence of the titanium content (in residual levels) in the turning operation performance with carbide tools, using two cutting speeds. The results show that the alloys with the highest titanium content generated the shortest tool life, but the titanium content influenced neither power consumption nor workpiece surface roughness. Attrition/adhesion was the main tool wear mechanisms verified in this work.

Carbon fiber-reinforced plastics (CFRP) are typical difficult-to-machine materials, which is easy to produce many defects such as burrs, dilacerations, layering in milling process. And selecting the appropriate cutting tool has become the key to machining CFRP with high quality and efficiency. In the paper, the machining principle of milling CFRP with new type end mill was analyzed. The diamond coating of general right-hand end mill, cross-flute router and fine-cross-nick router were used to cutting CFRP under the same cutting condition. Through the comparative analysis of the workpiece’s surface quality and tool wear, it concluded that: compared with right-hand diamond coated end mill, cross-flute diamond coated router or fine-cross-nick diamond coated router could effectively suppress the appearance of burrs and dilacerations; abnormal coating peeling appeared in the flank face of right-hand diamond coated end mill, forming the boundary wear, which accelerated wear failure; the flank wear of diamond coated cross-flute router and fine-cross-nick router were both abrasive wear. Due to having more cutting edge than cross-flute router in cutting process, the flank wear of fine-cross-nick router was slower, and the tool life was longer. So it was more suitable for cutting CFRP.

Application of the 3D reverse scanning method in the analysis of tool wear and forging defects

Hole precision is highly critical for accurate and strong fastener assembly. This factor is considerably important for structural materials, such as composite materials. Drilling is the most commonly used process for producing holes on composites. However, drilling causes excessive tool wear, which may affect the quality of holes and result in damage, such as delamination. The main objective of this study is to compare the drilling and punching processes in terms of tool wear by using the focus variation technique. The scanned images of both the puncher and drill bits are obtained by using a 3D optical surface measurement device called Alicona IFM. Tool wear patterns from both drilling and punching are analysed and compared, and the effects of the processes on the quality of the produced holes are observed.

Tool wear and heat transfer analyses in dry machining based on multi-steps numerical modelling and experimental validation