Search results for "TOOL"
showing 10 items of 821 documents
Friction and wear testing of multilayer coatings on carbide substrates for dry machining applications
2002
Abstract The principle aim of this paper is to investigate three wear-protective coatings with multilayer structures, which are frequently used in the cutting tool industry and to assess their frictional behaviour under the test conditions equivalent to those for the cutting of medium carbon steel. A modified pin-on-disc tester was used to conduct experiments in which both the friction coefficient and the linear wear of the tribo-pair were recorded vs. sliding distance. The volumetric wear rate was proposed as a parameter for quantitative comparison of the wear resistance of the tribo-pairs tested. It was found that the principle stage of the specimen wear takes place during the first 200–2…
Prediction of Tool Wear Progress in Machining of Carbon Steel using different Tool Wear Mechanismsl
2008
In this paper the prediction of tool wear on carbide uncoated tools was taken into account. In particular, two different tool wear models based on the diffusion mechanism and on the abrasion mechanism were considered. The calibration of the utilized models was done using the results obtained by experimental analysis performed on an orthogonally machined AISI 1020 tube. Once the calibration was executed, numerical simulations, for both the utilized tool wear models, were simultaneously performed with the aim to test the capability of the proposed numerical procedure. The comparison between the two tool wear mechanisms for predicting the flank tool wear is discussed in the paper.
Numerical simulations of the mechanical characteristics of glass fibre reinforced C-profiles
2006
A mechanical characterisation analysis on pultruded glass fibre reinforced C-shaped profiles, developed as modular construction elements to assemble fastening systems, such as doors, window frames and shutters is presented. The key idea is to perform the analysis, and all the related identification procedures of the material parameters, via a coupled approach, based on a limited number of standard laboratory tests and on the numerical finite element simulations of the same tests. The proposed approach allows one to identify all those material parameters which are difficult to detect, by means of simple laboratory experiments on specimens that are extracted from commercial products. It also …
Machinability of Engineering Materials
2008
Chapter 13 provides comprehensive knowledge regarding machinability of construction materials and characterizes various meanings of this specific material feature, allowing effective selection of machining conditions. Factors affecting machinability and typical causes of low machinability are discussed. Three groups of machinability criteria are selected, including basic, substitutive and auxiliary ones. In particular, the cutting speed corresponding to economic or high productivity criteria and obtainable surface roughness are distinguished as basic machinability criteria. Relative and absolute machining rating systems are highlighted, and appropriate material groups and values of the mach…
Influence of machining conditions on friction in metal cutting process – A review
2019
This paper presents a range of variable machining factors which influence substantially friction directly or by the tool wear developed in the cutting zone. The group of direct factors include the workpiece and cutting tool materials coupled, the cutting/sliding velocity, cooling media supplied to the tool-chip contact zone, modification of the tool contact faces by micro-texturing. Special attention was paid to the tool wear evolution and its pronounced effect on changes of the contact conditions.
Modeling the machined surface quality of an aluminum alloy using the active experiment type
2019
Abstract The surface roughness obtained by the cutting processes has always been a subject of great interest when it is intended to improve the quality of the final product requested by the customer. The objective of this scientific paper involves a comparative study on the tracking of the surface roughness measured both longitudinally and transversely in the direction of the cutting feed movement, following the end-milling process of an aluminum alloy used in the aerospace industry worldwide. Practical experiments have conducted in a prestigious company in the aerospace industry of Romania. Regarding the cutting regime, in terms of milling, a cutting speed was adopted to maintain its const…
Grinding Tungsten Carbide Used for Manufacturing Gun Drills
2015
This paper presents a study of grinding cemented carbide DK460UF (91 % WC and 9 % Co), a material used to produce cutting tools with solid cutting edges. The aim is to establish the manufacturing conditions that lead to high surface quality. A model of the main factors that influence the grinding process is presented first. Following that, grinding wheel wear and surface roughness are analysed. Grinding wheel wear is studied in experimental conditions under which small diameter gun drills were sharpened with two diamond grinding wheels of different grain sizes. Finally, the wear curve can be made. The "G ratio" is used to characterise the performance of the grinding process. Next, the exper…
Experimental investigation of the influence of adhesion on the frictional conditions in the cutting process
1999
Abstract This paper presents the results of an experimental study on the influence of adhesion on the tribological characteristics of the tool-chip interface. It was established that under orthogonal cutting conditions both the high interface temperature and severe plastic deformation result in relatively strong adhesion between steel and uncoated carbide. In particular, the molecular–mechanical theory of friction was applied to estimate the shear strength of the local adhesive junction, and to divided the rake face friction into two terms—an adhesion term (the interfacial coefficient of friction) and the deformation term. It should be pointed out that the data obtained provide a new approa…
Finite difference analysis of the thermal behaviour of coated tools in orthogonal cutting of steels
2004
Abstract Temperature measurement and prediction have been a major focus of machining for several decades but now this problem became more important due to the wider use of advanced cutting tool coatings. Practically, there is a lack of simulation programs for prediction of the temperatures in the cutting zone when machining with differently coated cutting tools. In all literature items cited the finite difference methods (finite difference approaches) were used to find the distribution of temperature inside the uncoated tool body or along the tool–chip interface for continuous (turning) and interrupted (milling) machining processes. The algorithm applied overcomes this limit. In this study,…
Wear Analysis During Friction Stir Processing of A359+20%SiC MMC
2009
Metal Matrix Composites (MMC) are very interesting materials for applications in the automotive and aerospace fields, since they combine the lightness of Aluminium with the strength of the ceramic reinforcement. These materials are very difficult to join and conventional welding techniques are not applicable, whereas solid-state welding techniques, like Friction Stir Welding (FSW), could be a solution. However very hard tool materials will need to be chosen in order to overcome the problem of heavy abrasive tool wear. In this work the wear behaviour of coated and uncoated steel tools has been investigated in the Friction Stir Processing of extruded bars in A359 + 20%SiC. AISI 1040 steel was…