Papers by Keyword: Coated Carbide Tool

Abstract: While machining a material, it is essential to understand the characteristics of work material for choosing the favorable condition of the material, appropriate cutting tool, machining parameters to achieve desired optimum output. Accordingly, researchers always devise their studies to improve the machining processes resulting in enhanced product quality and increased production rate simultaneously. Such machining studies on super-alloys attract significance, since they are oriented towards overcoming the difficulties involved in machined out a component. Generation of heat in the cutting zone and high cutting forces on the tool being experienced while machining super-alloys, are due to poor thermal conductivity and work hardening characteristics. Above factors contribute to two basic problems viz. the inability of the tool materials to give long tool life and the metallurgical damage to the machined components due to induced stresses. Among the super-alloys, Inconel 718 is the widely used heat resistant super alloy (HRSA), which withstands stringent operating conditions in high and cryo temperature environments for longer duration. Studies on understanding the behavior and the relationship between work piece material, cutting tool materials, cutting conditions and the process parameters is an essential requirement for establishing and optimizing the machining process and the present work is tailored towards this objective. In this work, Inconel 718 alloy was subjected to turning experiments and the experimental data collected was used for constructing empirical models whose performance was assessed through statistical approach. It is established that the models developed could be used for predicting the output parameters for a set of input of parameters through 2-D (surface) and 3-D (contour) plots.

Abstract: Inconel 718 is a material exhibiting characteristic that are able to maintain strength and integrity at elevated temperatures, but it is well known as a material with poor machinability. This paper presents a study of the performance in high speed machining of TiAlN/AlCrN nanomultilayer PVD coated Inconel 718 with minimum lubrication. Investigations have been made into the effects of cutting speed, feed rate and depth of cut (DOC) on the tool life. A toolmakers microscope and a scanning electron microscope (SEM) were used to examine the tool wear and chemical attrition, respectively, on the cutting tool during machining. In the machining of aged Inconel 718, the cutting tool experienced attrition, abrasion and notch wear throughout the experiment. Notch wear was found to be the dominant failure mode during milling; this wear appeared severe when localized flank wear reached the critical zone. The influence of radial depth despite the cutting speed, well known as having the most significant effect on tool life, is also discussed.

Abstract: In this paper, the optimization of cutting parameters is investigated to assess surface roughness and cutting force in the end milling of AlSi/AlN metal matrix composite. Eighteen experiments (L18) with five factors (cutting speed, feed rate, depth of cut, volume of particle reinforcement, and type of coated insert) were performed based on Taguchi designs of the experiment method. Two types of coating (TiB₂ and TiN/TiCN/TiN) of the carbide cutting tool were employed to machine various volumes of AlN particle (5%, 7% and 10%) reinforced AlSi alloy matrix composite under dry cutting conditions. Signal-to-noise (S/N) ratio and analysis of variance (ANOVA) were applied to investigate the optimum cutting parameters and their significance. The S/N analysis of the obtained results showed that the optimum cutting conditions for the cutting force were; A₂ (triple coating of the insert), B₂ (cutting speed: 200m/min), C₁ (feed rate: 0.6mm/tooth), D₁ (axial depth: 0.6mm) and E₁ (5% reinforcement). At the mean time, the optimum cutting conditions for surface roughness were; A₁ (single coating of insert), B₃ (cutting speed: 250m/min), C₂ (feed rate: 0.75mm/tooth), D₁ (axial depth: 0.6mm) and E₁ (5% reinforcement).The study confirmed that, with a minimum number of experiments, the Taguchi method is capable of determining the optimum cutting conditions for the cutting force and surface roughness for this new material under investigation.

Abstract: This paper deals with an experimental research on the wear mechanism of coated carbide tools in dry boring of the titanium alloys TC11 which are commonly used for aero-engines. The wear mechanism of coated tool inserts was investigated at various combinations of cutting speed, feed rate, and depth of cut. Analysis carried out with the SEM suggests that adhesive wear and coating delamination are the dominant wear mechanisms under low speed and feed rate and depth of cut; while chipping and breakage are the dominant wear mechanisms for the combinations of high cutting speed, feed rate, and depth of cut. There was no observation of oxygen existing based on the analysis of SEM which indicated no oxidation wear generated during the boring machining. The excellent chemical stability of TiAlN coating and oxidation resistance performance made contribution to prevent oxidation wear. Another reason was that boring temperature was lower than oxidation temperature.

Abstract: The aim of this work is to investigate the machinability of new coated carbide cutting tools that are named C7 plus coatings under turning of superalloy GH2132. This achieved by analysis of tool life at different cutting conditions .Investigations of tool wear and tool life testing are intended to establish T-V formulas, and then analyzed the characteristics of coating . Through a series of comparative tests, Using TiAlN coatings as the contrast materialthe results show that the new coating tools that are named C7 plus coatings are suitable for cutting superalloy GH2132. The cutting speed and processing efficiency can be increased effectively.

Abstract: In this paper, frictional behaviors of tool, workpiece and chip in turning particulate reinforced iron-based composites were investigated. Experimental results reveal that in frictional process, the frictional coefficient decreases with the normal force increasing or with the reinforcement content decreasing. In turning process, the variation rule of such parameter is just similar to that of frictional process, but frictional force and average frictional coefficient on rake face are more than that of frictional process. Meanwhile, the frictional mechanism of cutting tool and material is also studied. It indicates that adhesion occurs on tool-chip interface. The intense scratching of reinforcing particulates blocks the formation of adhesion layer and makes the frictional coefficient decrease, on the other hand, it increases the sliding resistance of chip, which makes the frictional coefficient increase. Since the latter is dominant, the tool-chip frictional coefficient increases with the increase in reinforcing particulates.

Abstract: This paper reports the results of an experimental works, where Inconel 718, a highly corrosive resistant, nickel-based super alloy, was finish-turning under high speed conditions. The machining processes were carried out at three different cutting conditions (DRY, MQL 50 ml/h and MQL 100 ml/h), three levels of cutting speed (Vc=90, 120 and 150 m/min), two levels of feed rate (f=0.10 and 0.15 mm/rev) and two levels of cutting depth (d=0.30 and 0.50 mm). The tool wear and flank wear progression were monitored, measured and recorded progressively at various time intervals. The experiments indicated that MQL condition performs better than dry condition in term of tool life. Most of the tool failures during machining were due to gradual failure where abrasive and notching wear on the flank face was the dominant followed by, fracture on the flank edge and nose radius. Tool failure due to crater wear was not significant. Wear mechanism such as abrasive and adhesion were observed on the flank face and diffusion wear was observed on the rake face.

Abstract: The results of the experimental researches show that the high speed cutting tool is disabled in two modes of gradual wear and rapid breakage as HSC proceeds. Tool breakage occurs in low speed cutting. In process of HSC, the tool disability is the combination of flank face wear, boundary wear and cutting edge slope-plane wear. Under the action of the tool cutting movement, the ridges and furrows and burntthrough speckles and the molten metal daub phenomena come into being on the machined surface. With cutting speed increasing, it is weakened that tool wear has adverse effects on the forming of machined surface, and the workpiece surface quality is improved to a certain extent.