Search results for "Drawing."
showing 10 items of 470 documents
Method for Manufacturing Custom-Shaped Prosthetic Parts from Titanium Alloys by Incremental Forming Using Industrial Robots
2014
The last decade has shown an increasing interest in a new class of forming processes known as Incremental Sheet forming (ISF). A possible application for this new procedure, targeted by the authors of this paper, is the manufacturing of custom-shaped prosthetic parts for use in various areas of human medicine. Such prostheses can have a functional role, when they target the replacing of a functional component of the human body, or an esthetic role, when they target the solving of problems related to the appearance of the human body. In this paper the authors aim to determine the strain hardening curves for the titanium alloy Ti6Al4V at room temperature and at 800°C. The incremental forming …
Joining by plastic deformation
2013
Abstract As the scale and complexity of products such as aircraft and cars increase, demand for new functional processes to join mechanical parts grows. The use of plastic deformation for joining parts potentially offers improved accuracy, reliability and environmental safety as well as creating opportunities to design new products through joining dissimilar materials. This paper aims to provide an overview of the state of the art in such joining processes, including cold welding, friction stir welding, self-pierce riveting, mechanical clinching and joining by forming. The paper includes description of the mechanism of joint formation, and analysis of joint performance and applicability.
Effectiveness of numerical simulation in avoiding defects in hot extrusion forging products
1999
The hot extrusion forging, in the production of an half shaft of a motorcycle engine, has been analysed by means of finite element simulations. The severe mesh distortion occurring in the simulation has been overcome with the aid of a code provided with automatic remeshing techniques. The study is aimed to promote the use of FEM not only in the designing phase but also as a tool able to investigate defects occurring at the production level.
Thermophysical-Property-Based Selection of Tool Protective Coatings for Dry Machining of Steels
2003
A method is proposed for determining the optimum cutting conditions in dry turning of carbon and stainless steels using multilayer coated tools for physical criteria such as the maximum temperature of a cutting tool or maximum heat flux. The modified thermal number describing the tool-chip behavior, is introduced. The correlation between the thermal number and the average tool-chip interface temperature and frictional heat flux is examined for both flat-faced and grooved rake configurations. Although not shown here directly, the thermal barrier effect observed for multilayer coatings with an intermediate Al2O3 layer increases the heat partition to the chip at substantially reduced cutting t…
Cutting Tool Materials
2008
This chapter provides the state-of-the-art materials engineering sector that produces cutting tool materials for different manufacturing branches. It highlights the special demands on this special material group for modern machining technologies. Five groups of cutting tool materials are characterized in terms of their mechanical and thermo-physical properties: high-speed steels, sintered tungsten carbides, cermets, ceramics and superhard materials, all as conventional (uncoated) and coated grades. The most popular techniques of coating deposition on various substrates are described. Practical examples of cutting tool inserts made of various materials produced by leading world manufacturers…
Cutting Temperatures Evaluation in Ceramic Tools: Experimental Tests, Numerical Analysis and SEM Observations
1994
The authors propose a multiple approach for the evaluation of cutting temperatures in ceramic tools. The first approach was the experimental evaluation of equitemperature lines, obtained in three-dimensional cutting by employing constant melting point powders scattered on planes parallel to rake face. In the second approach, a numerical finite element analysis was performed. At this step the determination of the percentage of total heat produced in the operation that flows into the tool was considered and, consequently, the temperature distribution within the whole volume of the insert. Finally, the examination of the crater zone with SEM microscopy confirmed the temperature levels as previ…
Residual Stresses due to High Temperature Annealing. Mathematical Model and Calculations
2006
The mathematical model is developed for description of thermomechanical processes at cooling during high temperature annealing with the known initial temperature distribution (the temperature of holding) and stresses (acquired stresses at the final of a holding). It is taken into account the thermal sensitivity and material hardening at elasto-plastic solid deforming. The methodology based on the finite element method is proposed for solving thermomechanics problems of wide range. The suitable software is developed. At the final stage of annealing a cylindrical solid it is investigated residual stresses being formed on the cooling stage.
A computational approach to evaluate temperature and heat partition in machining with multilayer coated tools
2003
Abstract In this paper, analytical models for estimating the interface temperature and heat partition to the chip in continuous dry machining of steels with flat-faced tools treated with multilayer coatings are presented. The database for modeling includes changes in the thermal properties of both workpiece and substrate/coating materials and the Peclet and Fourier numbers occurring at actual interface temperatures. Process outputs involve the average tool–chip interface temperature, the tool–chip contact length, the friction energy and the heat balance between the moving chip and stationary tool. It was found that the heat partition coefficient varies significantly from 0.65 to 0.8 when us…
Determination of Nonuniform Residual Stresses Using the Ring-Core Method
1996
This paper considers residual stress analysis using the ring-core method. In particular, the so-called integral equation method is applied to evaluate nonuniform residual stress fields. The proposed method overcomes typical drawbacks of the incremental strain method which lead to incorrect results for strongly varying stress fields. The experimental results obtained with a specimen subjected to a bending load confirm the theoretical predictions.
Automatic Recognition and Analysis of Scanned Non-crimp Fabrics for Calculation of their Fluid Flow Permeability
2007
Automatic recognition of scanned images of distorted bi-axial fiber bundle arrangements is considered in order to obtain the overall permeability of the formed fiber network. Scanned images are pre-processed with color normalization followed by usage of a threshold to find the pixels belonging to the bundles, the threads keeping the bundles together, and the distinct gaps formed between the bundles. Since the scanned images virtually have a perfect grayscale, the intensity can be treated as a corresponding signal of the image. Next the regular character of the fiber network is investigated using Fourier analysis on the fiber bundles as well as on the threads. The direction, position, and s…