Cemented Carbide Cutters Research Articles

The Study on Optimization of Cutting Parameters to Enhance Surface Finish

Abstract: The Objective of this project work is to Productivity and Surface finish improvement in CNC Die and Punch machining through optimization in cutting parameters. This technical paper studies the different machining parameters i.e. DOC, cutting feed and cutting speed by using different material cutters like cemented carbide cutters, HSS cutters, Insert types cutters. In this thesis an attempt to make use of Japanese optimization technique to optimize cutting parameters during highspeed milling of aluminum alloy using cemented carbide cutting tool

OPTIMIZATION OF CUTTING PARAMETERS TO ENHANCE SURFACE FINISH

The Objective of this project work is to Productivity and Surface finish improvement in CNC Die and Punch machining through optimization in cutting parameters. This technical paper studies the different machining parameters i.e. DOC, cutting feed and cutting speed by using different material cutters like cemented carbide cutters, HSS cutters, Insert types cutters. In this thesis an attempt to make use of Japanese optimization technique to optimize cutting parameters during high-speed milling of aluminum alloy using cemented carbide cutting tool.

Characterization and mechanism of cutter parameters in tubing milling

Downhole string milling is becoming increasingly difficult due to the increasing complexity of oilfield development technology and material quality advances, especially for downhole tubing milling. In this paper, a Lagrangian modeling approach is used to investigate the mechanism and effects of cutting parameters on tubing milling characteristics. The cemented carbide cutter parameters, including the cutting angle, lateral angle, weight on cutter, and rotating speed, are determined to obtain the maximum cutting rate. A cutting tool is designed, manufactured, and tested. The simulation results are in good agreement with the test results, yielding the maximum equivalent stress generated by the cutter of 1163 MPa, which is much higher compared to the tubing yield strength. The tubing cutting volume and mass increased with the cutting angle, up to 12.5°, while the maximum value obtained using the lateral angle is 5°. With an increase in weight on cutter, the maximum von Mises equivalent stress and equivalent strain generated by the cutter also increased. Furthermore, the cutting volume and mass increase rapidly with the rotational speed at the start, followed by a slow increase when the rotational speed is above 70 rpm. The cutter mainly generated continuous chips. Finally, industrial tests are successfully carried out, confirming the milling efficiency increase of 40.1% compared to the traditional milling methods.

Design of surface micro texture in the cutter-chip contact area of a cemented carbide cutter

Placing micro textures on a cutter surface can enhance the cutter-chip and cutter-workpiece contact, improving the cutter performance and machined surface quality. However, both the proper placement of micro textures and careful modeling of their density function are required for optimizing the cutting performance. In this study, a ball end milling cutter was utilized to demonstrate how these can be achieved. Initially, the theoretical cutter-chip contact length of the was calculated based on the chip curl theory and the theoretical cutter-chip contact area was obtained by combining the theories of cutter contact area and micro texture placement. Then, a mathematical model describing the micro texture distribution was established using a uniform density function, which allowed the determination of the specific distribution model for the micro textures. Finally, both simulations and experiments were used to validate the accuracy of the theoretical solution for the cutter-chip contact area and the uniformity of the micro texture density function. The results showed that the theoretical cutter-chip contact area and the uniform micro texture density mathematical model are consistent with the simulation and experimental results. The results reported in this paper provide a theoretical basis for the accurate preparation of micro textures.

Built-up edge formation mechanisms in orthogonal cutting of wood-plastic composite

ABSTRACT This project aims to improve the machinability of wood-plastic composites by understanding chip and built-up edge formation, so as to help manufacturers optimize cutting performance and product quality. Chip formation and built-up edge were studied during orthogonal cutting of wood polyethylene composite with cemented carbide cutters under different conditions. During the orthogonal cutting process, segmental, ribbon, and element chips were generated. The cutting depth was found to have a great impact on the types of chips that formed. Additionally, a built-up edge was found during wood-plastic composite machining, with debris only attaching to the tool's rake face due to thermo-mechanical coupling. Such built-up edges hinder cutting stability and surface quality. Furthermore, variations in the accumulation of debris on the built-up edge corresponded to changes in cutting force and temperature. In fact, both cutting force and temperature proved to be inversely related to the rake angle and positively correlated to the cutting speed and depth. Therefore, to achieve better cutting stability and surface quality for wood-plastic composites, a larger rake angle and a reduced cutting depth are recommended because they reduce the accumulation of debris and the formation of built-up edge.

Machinability of Different Wood-Plastic Composites during Peripheral Milling.

The aim of this study was to improve the machinability of wood-plastic composites by exploring the effects of different wood-plastic composites on machinability. In particular, the effects of milling with cemented carbide cutters were assessed by investigating cutting forces, cutting temperature, surface quality, chip formation, and tool wear. The cutting parameters determined to yield an optimal surface quality were rake angle 2°, cutting speed 9.0 m/s, feed per tooth 0.3 mm, and cutting depth 1.5 mm. In these optimized milling conditions, the wood-plastic composite with polypropylene exhibited the highest cutting forces, cutting temperature, and tool wear, followed by polyethylene and polyvinyl chloride wood-plastic composites. Two wear patterns were determined during wood-plastic composite machining, namely chipping and flaking. Due to the different material composition, semi-discontinuous ribbon chips and continuous ribbon chips were generated from the machining process of wood-plastic composites with polypropylene and polyethylene, respectively. The wood-plastic composite with polyvinyl chloride, on the other hand, formed needle-like chips. These results contribute to a theoretical and practical basis for improved wood-plastic composite machining in industrial settings.

Study on the Properties of Coated Cutters on Functionally Graded WC-Co/Ni-Zr Substrates with FCC Phase Enriched Surfaces

Currently, the research on mechanical behavior and cutting performance of functionally graded carbides is quite limited, which limits the rapid development of high-performance cemented carbide cutting tools. Based on WC-Co-Zr and WC-Ni-Zr, this study synthesized two kinds of cemented carbide cutters, i.e., the cemented carbide cutters with homogeneous microstructure and functionally graded carbide (FGC) cutters with FCC phase ZrN-enriched surfaces. Furthermore, TiAlN coating has been investigated on these carbide cutters. Mechanical behavior, friction, wear performance, and cutting behavior have been investigated for these coated carbides and their corresponding substrates. It was found that, as compared with coated cutters on WC-Co/Ni-Zr carbide substrates with homogeneous microstructures, the coated cutters on WC-Co/Ni-Zr FGC substrates with FCC phase-enriched surfaces show higher wear resistance and cutting life, and the wear mechanism during cutting is mainly adhesion wear.

Properties of variable distribution density of micro-textures on a cemented carbide surface

Titanium alloys are difficult-to-machine materials that exhibit a low machining efficiency, yielding its restricted applications. The combination of micro-textures and a cemented carbide surface cutter can effectively improve the cutting performance and enhance titanium alloys' machining quality. Therefore, this manuscript investigates a cemented carbide ball-end milling cutter with surface modifications. Firstly, we prepared micro-textures with a variable distribution density on the surface of a cemented carbide cutter and revealed its properties from the microscopic aspect based on the simulation and test methods. Secondly, a milling test was done to reveal the anti-wear and anti-friction properties accuracy. Finally, based on the test data, the Lasso regression prediction models were established. Based on the Matlab particle swarm optimization algorithm, the parameters of micro-textures with a variable distribution density were optimized.

Effects of temperature and loads on hardness and surface failure modes of cemented carbide

Cemented carbide is a common cutting material with a hardness that significantly affects its usability. A Vickers indentation test was performed to analyse changes in the hardness of cemented carbide cutters with temperature and loads to understand its variation law. Moreover, indentation-induced surface damage was observed, and its elements were analysed. Crack distributions on the indentation surface were detected and analysed through an etching method. The results demonstrate that the hardness of cemented carbide decreases with greater temperatures and loads. At room temperature, the hardness of cemented carbide decreased from 1321 to 996 MPa when the loads increased from 300 to 800 N. When the external load was fixed at 500 N, the hardness of the cemented carbide decreased from 1113 to 939 MPa as the temperature increased from 25 to 350 °C. Moreover, the density of the indentation-induced surface damages increased with a reduction of the Vickers hardness. In addition, the mean free path of the binding phase for the cemented carbide with large grain sizes was relatively high. Therefore, it is difficult to generate diagonal cracks under large loads and high temperatures, which are beneficial to prevent cutter flaking.

Influence of machining parameters on the polymer concrete milling process

The paper examines the wear of end mill cutters, the parameters of a workpiece’s surface layer and the values of cutting forces during the machining of polymer concrete, which is one of the most difficult-to-cut materials. Increased abrasive wear of the active cutting edges is a result of the heterogeneous structure of this material, and it has a negative effect on the cutting process, the durability of the cutting tools as well as the roughness of the workpiece. It is very important to determine the machining parameters for this material from a tool durability and quality of machining point of view. The research was divided into two stages. In the first stage, the appropriate machining parameters were determined based on the measurement of the components of the cutting force. In the second stage, durability tests of four end mill cutters were carried out. During the tests, the component cutting forces, tool wear and surface roughness were measured. The highest tool durability was recorded for the monolithic cemented carbide cutter with coating NC Mill G9F42120N 4F. Tools made of high-speed steel should not be used for machining polymer concrete, as they exhibited the highest intensity of tool wear. The rapid loss of machinability of these tools leads to a rapid increase in cutting force and the roughness of the machined surface. From an economic point of view, cemented carbide end mill cutters with coatings seem to be the appropriate choice for machining polymer concrete.

Error compensation model considering tool wear in milling difficult to cut materials

In this paper, error compensation considering tool wear is studied to improve machining precision of difficult-to-cut material in milling process. First, an error model considering tool wear in milling process is established based on the relationship between the position angle and the radius of the section circle of ball-end milling cutter, and the established error model is solved and verified. Then, based on the verified error model, a new error compensation method based on a scale division idea is proposed to determine the required compensation value and generate the compensated tool path by tracing the initial tool path and tool wear deviations. Based on the above error compensation method, the detailed compensated processes for a plane, cylindrical surface and sculptured surface are analysed and an off-line error compensation software is developed by using Visual C++ programming tool. Finally, experimental tests performed with stainless steel 1Cr18Ni9Ti and cemented carbide cutters, are used to validate the reliability of the proposed error compensation method in milling operations. Experimental results show that the proposed error compensation method can reduce machining error and improve machining surface quality.

Failure analysis of WC-3.5wt%Co cemented carbides in mining Applications

In order to further understand the wear mechanisms of cemented carbide cutter head of conical pick, six wornout cutter heads were investigated detailedly through scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS). Abrasion wear and tipping were found to be the main wear mechanisms of the worn out cutter heads. Thermal stress and impact load played important roles in the wearing process of cutter heads. The intermixed mineral particles in the worn out areas aggravated the wear on the surface of cemented carbide. The spherical particles and vine-like structures were found to distribute in the wornout areas arbitrarily, and the compositions of which were detected using EDS.

Study on the Temperature Field of Cemented Carbide Substrate in Miniature EACVD System

The uniform distribution and the stability of the substrate temperature are the most important factors that deeply affect the quality and the growth rate of diamond films. In this paper, cemented carbide cutters were chosen for substrates, the 3D finite element (FE) model of filaments and substrates was developed in ANSYS 8.0, the calculated results show that the substrate temperature is influenced by the filament temperature, filaments diameter, the quantity of the filaments and the distance between the filaments and the substrates. The 3D finite element model of filaments and substrates also provides a basis for selecting the parameters to obtain uniform diamond films in miniature EACVD system.

A new-type of cermets cutter with nano-TiN addition: Microstructure mechanical and cutting properties

The microstructure and mechanical properties of a new-type of cermets cutter (tool A) with nano-TiN modification and its cutting properties in cutting gray cast iron are investigated. SEM and TEM observations of the microstructure of the above material reveal that nano-TiN modified cermets possess a finer microstructure than conventional cermets. In the cutting tests, for comparison, cemented carbide cutter (YG8, tool B) was also utilized. The cutting results show that the cutting properties of tool A are superior to those of tool B. It is also found that the predominant failure mode of tool A is normal wear and micro-spoiling under lower cutting quantities, and that chipping occurs under higher cutting quantities. SEM analysis reveals that cohesion, oxidation and diffusion wear become very apparent at a higher cutting speed. On the contrary, grain wear also exists but is not apparent.

Experimental Research on ELID Grinding and Cutting Performance of Nano Cemented Carbide Cutters

Nano cemented carbide is a new style cutter material. Because its grain size is very small, it is superior to common cemented carbide in properties, such as high hardness, fracture toughness, flexural strength and higher abrasion resistance. As a cutter material, nano cemented carbide has wide use. In this paper, nano cemented carbide tool was ground with ELID technology, and the cutting properties of nano cemented carbide were studied, and the difference in cutting properties among the ultra-fine grain, common cemented carbide and nano cemented carbide was analyzed under the same condition. Results imply that the ground surface roughness of nano cemented carbide is obviously lower than that of common cemented carbide, and the tool life of nano cemented carbide is 5-7 times longer than that of common cemented carbide at low cutting speed.

Improvement of hot forging manufacturing with PVD and DUPLEX coatings

The application of a DUPLEX treatment, which included low pressure pulsed plasma nitriding of AISI H11 tool steel dies and PVD BALINIT® FUTURA-TiN/TiAlN multilayered coating, was studied as a possible technology to improve the process of hot forging of steel components. The quality of the DUPLEX treatment was determined by laboratory analyses of coated test plates, which were treated together with the hot forging dies. Surface roughness, Vickers microhardness including in-depth measurements, coating thickness and adhesion parameters determined by the REVETEST method and microanalysis (SEM and EDS), were investigated. Performance tests were made in real working conditions in the UNIOR hot forging industry in Zreče, Slovenia, and included three types of technological processes: (a) form milling of graphite electrodes (to produce dies by the electrical discharge machining process with cemented carbide cutters improved with a BALINIT® Diamond coating); (b) hot forging of steel components (with two step forging dies fixed in a 1650 t eccentrically driven press, improved with the DUPLEX treatment); (c) hole punching in forged parts (with dies made of ASP30 tool steel and improved with a standard PVD TiN coating). The hole punching in forged parts and milling of graphite electrodes were performed successfully in practice for many years. In hot forging, the first positive results were obtained after three experimental studies in the last two years. Optimisation of the parameters of the DUPLEX treatment is still needed before this technology can be introduced into regular manufacturing operations for hot forged steel parts.

Adhering wear mechanism of cemented carbide cutter in the intervallic cutting of stainless steel

This paper describes the interface adhesion behavior between the cutter and work piece when austenitic stainless steel is milled by cemented carbide cutter. It is shown that: (1) At medium cutting speed, adhering layer is formed between the rake face and the chip. Plastic deformation and recrystallization or melting has taken place at the interface between the rake face and the adhering layer. This phenomenon is similar to friction welding. (2) At low cutting speed, no adhering layer exists on the rake face. Only small areas are stuck or welded between the rake face and the chip underlayer. Rupture of the joint might occur in the weaker side, and many valleys are formed on the rake face. (3) At high speed, the crater is formed on the rake face: adhering phenomenon does not occur.