Papers by Keyword: Tool Wear

Abstract: In today’s industrial scenario, the requisite for elevated efficiency, better economic viability and higher quality asks for immense improvements in the cutting process stability. Such machining at higher cutting speeds and cutting depths causes an immense amount of heat generation at the work tool interface. The industry makes utilization of cooling techniques to contravene these ill-effects. These techniques make utilization of chemical coolants which are non-biodegradable in nature and consumed in immense quantities. In this study the role of minimum quantity lubrication (MQL) or green machining was experimentally evaluated when utilizing nanoparticle enriched coolants. The effect on the wear and roughness values while turning commercially pure Titanium (Grade 3) was analyzed. Experimentation was performed in two phases. In the first phase, the comparison in dry, flood and MQL process was made. The experimental design was composed factorially and 16 experiments were performed. Analysis was carried out utilizing ANOVA and the results were compared. In the second phase, a graphical cognation was established between the coolant application rate with both surface roughness and flank wear values. It was concluded that the nanoparticle enriched coolant i.e. the “eco nanomist”technique was more efficacious when machining the biocompatible Titanium grade 3.

Abstract: Inconel 718 is a nickel-based super alloy well suited for high-temperature applications encountered in space shuttles, aircraft black box and turbocharger due to their inherent properties. Taking into account of extreme working conditions, efficiency in the process of machining without affecting the nature of the surface integrity with utmost care assumes a lot of importance. In this current study, an attempt has been made to investigate the influence of cutting speed and feed rate on various machining aspects like cutting forces, chip morphology, surface roughness and tool wear during the orthogonal turning of Inconel 718. Also, the work has been focused on feed forces and thrust forces to understand the proper material deformation behaviour and surface integrity.

Abstract: The study analyzes physicomechanical and thermophysical properties of hard alloys with due regard to their chemical composition; reveals the dependence of both the cutting properties and regularities of carbide tool wear from cutting conditions and thermophysical properties of tool material; describes a significant impact of not only mechanical but, first and foremost, thermophysical properties of instrumental and structural materials on tool wear; and identifies ways to reduce the wear rate of a cutting tool.

Abstract: Glass, being considered as hard and brittle material is very difficult to machine into desired shapes. The readily available conventional machining process does not provide good surface finish thus requires additional machining process. This paper reviews the different existing non conventional machining process accessible till today for the machining of glass materials. This paper also discusses the advantages and disadvantages of the existing non conventional machining processes. The various hybrid non conventional machining processes are also studied with focus on machining output characteristics like MRR, surface finish, tool wear rate. This paper summarizes the selection of hybrid non conventional machining processes for the various type of glass.

Abstract: In order to improve efficiency of high speed milling, effects of pick feeds of up cutting and down cutting on tool wear and processing characteristics were investigated after cutting pre-hardened steel NAK 55 by TiAlN-coated carbide radius end mill. Flank wear of the tools after up cutting was less than down cutting when the pick feed was smaller than 0.1 mm, which tendency changed when the pick feed was larger than 0.3 mm.

Abstract: The use of thermal spray coatings is increasing to improve abrasion resistance, erosion and corrosion resistance. To improve the dimensional accuracy or surface roughness, it is often necessary for thermally-sprayed machine parts to be machined by the removal process. As thermally-sprayed coatings often show difficult-to-cut properties, a cutting, grinding, or honing process is usually employed. Replacement of the grinding process with a cutting process is an effective method for improving productivity. Cutting is performed intermittently because there is a hole in the ball part. However, there are no studies on intermittent cutting of thermally-sprayed coatings. In this study, in order to obtain an effective tool material for intermittent cutting of two types of the thermally-sprayed coating AISI 304, the tool wear was investigated experimentally. The results are as follows: (1) In the case of intermittent cutting of Ni-based self-fluxing alloy coating AISI 304, S_i3N₄ ceramics were considered an effective tool material. (2) In the case of intermittent cutting of thermally-sprayed (WC-Cr-Ni) cermet coating AISI 304, the uncoated cBN having the large grain size of cBN and a high content rate was effective for wear resistance.

Abstract: Turning of hardened alloy steel (Hard turning) is a replacement for grinding operation. The heat generation and temperature during hard turning at the cutting zone and due to the friction at tool-chip-workpiece interface are significant parameters which influence chip formation mechanism, tool wear, tool life, surface integrity and hence the machining quality. Cutting fluid performs key role in metal cutting due to its cooling and lubrication action. Flood cooling is a common method of cutting fluid application, in which large quantity of cutting fluid is applied at the cutting zone. Due to environmental, health and safety concerns, the usage of cutting fluid in abundant quantity is being restricted. Most of the researchers have varied the cutting parameters like cutting speed, feed rate and depth of cut to machine different work materials with different cutting tools and studied its effects on cutting force and cutting temperature. It is thus essential to study the combine effect of cutting and jet parameters in machining. This research article focusses on study and optimization of cutting and jet parameters on tool-chip interface temperature and cutting forces during turning hardened alloy steel AISI 4140 steel of 50 HRC using Finite Element Analysis and Taguchi’s Technique. Three levels of cutting speed, feed rate, depth of cut, jet angle and jet velocity are chosen. A suitable L27 Orthogonal array is selected based on Taguchi’s Design of Experiments (DoE) and the output quality characteristics such as tool-chip interface temperature and cutting forces are analyzed by Signal-to-Noise (S/N) ratio. Analysis of Variance is performed to determine the most contributing factor, which shows that the feed and depth of cut are the most prominent contributing parameter followed by cutting speed, jet impingement angle and jet velocity.

Abstract: In this study, an attempt has been made to develop a predictive model for tool nose wear. A well planned experimental design was utilized for this purpose using the design of experiment approach. From this research work, it was found that cutting speed (s), feed (f) and their interaction having the main effect on cutting tool performance. Using ANOVA analysis significance and contribution of each machining parameter and their interaction is also analyzed. Hence, a predictive model was developed to predict tool nose wear by using the various machining parameters and its adequacy was also checked for the prediction purpose.

Abstract: The experimental investigation of process characteristics while performing micro-milling on hybrid aluminium metal matrix composite is discussed in this article. High Speed Steel micro end mill cutters are used for machining of micro-slots on Al6063 metal matrix composite reinforced with zirconia and silicon carbide. The tools are also treated cryogenically at -196°C using liquid nitrogen with a holding time of 24 hours. For this investigation, machining parameters like feed rate, cutting speed and depth of cut are considered as the process parameters. The effect of the process parameters on the material removal rate and surface roughness for hybrid metal matrix composite are analyzed. In addition, tools wear for untreated and cryo-treated single tempered tools are also investigated. The output responses i.e., material removal rate and surface roughness of cryo-treated tools exhibit better results than untreated tool due to increase in strength, hardness and wear resistance.

Abstract: The difficulties of machining nickel-titanium alloys are due to their high ductility and super-elasticity, strong strain-hardening, and excellent wear resistance. These characteristics lead to poor chip breakability, high cutting forces, rapid and aggressive tool-wear, as well as excessive burr formation during mechanical machining processes. The present study addresses these issues by evaluating the effects of drilling parameters and drill bit coatings on the growth of tool wear and development of the drilling thrust force. The findings from this research indicate that the TiAlN coated carbide drill was found to significantly improve the wear resistance of the cutting tool. Likewise, the results of thrust force development are consistent with the trends of tool wear growth for all of the tested carbide drills.