Search results for "Carbide"
showing 10 items of 139 documents
A New On-Line Roughness Control in Finish Turning Operation
1996
A new on-line control method for the wear state of sintered carbide tools for finish turning operations is proposed.
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…
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…
Finite element modelling of temperature distribution in the cutting zone in turning processes with differently coated tools
2005
Abstract The aim of this study is to check the applicability of various simulation models to obtain finite element solutions of cutting forces, specific cutting energy and adequate temperatures for a range of coated tool materials and defined cutting conditions. Commercial explicit finite element code Thirdwave AdvantEdge has been used in simulations of orthogonal cutting processes performed by means of uncoated carbide and coated tools. The latter were equipped with progressively increasing number of thin layers including TiC, TiN and Al 2 O 3 films deposited onto ISO P20 carbide substrates. Results showing the tool–chip interfacial friction influencing the temperature distribution fields,…
Analytical Models Based on Composite Layer for Computation of Tool-Chip Interface Temperatures in Machining Steels with Multilayer Coated Cutting Too…
2005
In this study the method of elementary balances (MBE) is applied to predict the temperature fields in uncoated and coated carbide cutting tools. Numerical computations are supported by the experimentally/analytically obtained values of the contact length, the total heat flux and the heat partitioning. The changes in the tool temperature maps, resulting from variable thermal properties of tested materials are considered. In particular, the distribution of temperature across the thin film of 0.01 mm and corresponding temperature rise distribution curves along the rake and flank faces are completely displayed. The simulations have been validated against the measured average rake face temperatu…
Wear modelling in mild steel orthogonal cutting when using uncoated carbide tools
2007
Abstract Wear prediction in machining has been recently studied by FEM although the use of numerical methods for such applications is still a very challenging research issue. In fact, wear phenomenon involves many aspects related to process mechanics which require a very accurate modelling. In other words, only a very punctual code set-up can help the researchers in order to obtain consistent results in FE analysis. The high relative velocity between chip and tool requires effective material models as well as friction modelling at the interface. Moreover the prediction of temperature distribution is another critical task; in the paper some different procedures are discussed. Subsequently a …
First Characterization of Novel Silicon Carbide Detectors with Ultra-High Dose Rate Electron Beams for FLASH Radiotherapy
2023
Ultra-high dose rate (UHDR) beams for FLASH radiotherapy present significant dosimetric challenges. Although novel approaches for decreasing or correcting ion recombination in ionization chambers are being proposed, applicability of ionimetric dosimetry to UHDR beams is still under investigation. Solid-state sensors have been recently investigated as a valuable alternative for real-time measurements, especially for relative dosimetry and beam monitoring. Among them, Silicon Carbide (SiC) represents a very promising candidate, compromising between the maturity of Silicon and the robustness of diamond. Its features allow for large area sensors and high electric fields, required to avoid ion r…
Ohmic Contacts on p-Type Al-Implanted 4H-SiC Layers after Different Post-Implantation Annealings
2019
This paper reports on the electrical activation and Ohmic contact properties on p-type Al-implanted silicon carbide (4H-SiC). In particular, the contacts were formed on 4H-SiC-implanted layers, subjected to three different post-implantation annealing processes, at 1675 °
On the Influence of the Radius Between Face and Flank on the Tool Life of Sintered Carbides
1985
Experimental investigations carried out by the authors in interrupted cutting, show that if the cutting edge survives to few impacts, then fracture will take place to very high number of impacts. Early fractures can be explained by assuming the presence of microscopic defects on the tool edge; a longer life can be referred to an increase tool strengthness due to rounding of the edge as a consequence of the wear process. In order to study the effects of the rounding of the edge, experimental tests have been carried out on several inserts of sintered carbides with different values of the radius of the edge between face and flank obtained by a tumbling process. The results show that the greate…
Determination of cobalt, copper, iron, nickel and zinc in cemented tungsten carbides with cobalt as a binder by FAAS: Matrix effect control by multiv…
1997
A new approach for the determination of cobalt, copper, iron, nickel and zinc in cemented tungsten carbides with cobalt as a binder by flame atomic absorption spectrophotometry (FAAS) is reported. Real samples were dissolved in phosphoric, hydrochloric and nitric acid. PTFE bomb or alternatively small amounts of HF were used for the enhancement of the recovery of the elements investigated. Synthetic samples were used for interference studies. Multiple linear regression was applied for the control of matrix effects and it proved to be very effective in the search for interfering elements. Using simple acid based standards, all investigated elements could be determined sequentially in a compl…