Tool Wear Characteristics Research Articles

Use of ceramic tools for machining nickel based alloys

The paper is the first of two dealing with the use of ceramic tool materials for the machining of nickel based alloys. While the second contribution presents the results of detailed machinability tests, involving a cross-section of current nitride, superhard and whisker reinforced ceramic tooling products, this first paper comprehensively reviews existing literature on the subject. Following an assessment of tool wear characteristics, such as depth-of-cut notching and the underlying mechanisms involved, in particular the effects of applied mechanical stress and high interface temperatures, details are given of the composition, structure, physical properties and cutting performance of various state-of-the-art ceramic tool materials. Although only recently available commercially, whisker reinforced composite tools, comprising an alumina matrix with approximately 25% by volume silicon carbide whiskers, are reported to be capable of operating at cutting speeds up to 750 m/min on some nickel based alloys.

切削工具寿命の解析的予測に関する研究(第4報)

Flank wear characteristics of tungsten carbide tools in turning plain carbon steels without built-up edge have been investigated by measuring temperature, normal stress and wear rate on the flank wear land. It is found that the crater wear characteristic equation, derived from the adhesive type wear model after M. C. Shaw in the previous paper, is able to describe the flank wear as well. However, the characteristic equation of flank wear consists of two characteristic lines with different gradient which intersect at the critical temperature of around 1150 K. It seems that the line in the low temperature side is affected by abrasives in the steels. This abrasion effect could be taken into account by changing the constants involved in the wear characteristic equation. On the other hand, an abrasive type wear equation could be derived so as to have the same expression as our wear equation. Observation of the wear particles by Uehara, however, appears to exclude the possibility of this wear model.

Tool wear characteristics in ultrasonic drilling

The behaviour of certain specific tool and work material combinations with respect to tool wear under the influence of different parameters in ultrasonic drilling are discussed in this paper. The results will help the process user to arrive at the optimum tool-workpiece combination and other machining parameters and to decide the best method of preparation and heat treatment of the tool.

Flank Wear Characteristics of Cutting Tools in Different Types of Tests : Comparison between Results of Conventional Turning, Step Turning and Facing Tests

Although the performance of cutting tools has been evaluated by the tool-life values in the conventional turning tests, it is difficult to apply such data for the estimation of tool wear characteristics in different types of cutting tests. The purpose of this study is to clarify the relationships between various test results on flank wear. Three types of cutting tests, i.e., conventional turning, step turning and facing tests are performed on mild steel withsintered carbide tools. The tool wear growth curves of all tests are respectively formulated based on a few assumptions. The wear rate, which is defined by the wear land width per unit cutting length excepting the initial wear, is mainly used for analyzing the results. Thus, some relations are revealed between the results of above three tests ; a significant difference is recognized in the wear rate between facing test and the other two tests.

Tool wear and tool life characteristics of unconventional sintered carbides in the intermittent cutting of hardened steel

Carbides coated with TiC, TiN, TiC/TiN or TiC/Al 2O 3 coatings on a tough hard material base and TiC-containing hard material of modified composition and structure were used to investigate tool-wear and tool-life characteristics in face milling of martensitic steel of hardness 300–600 HV. Tool-life behaviour with increasing hardness and cutting speed was determined. Characteristic wear mechanisms are discussed on the basis of light and scanning electron microscopy observations.

GFRP切削時の工具摩耗特性

GFRP切削時の工具摩耗特性

The effect of grain size on the wear characteristics of high speed steel tools

The effect of variation in austenite grain size between intercept size no. 12 and no. 25 on high speed steel (h.s.s.) tool performance was studied for continuous and intermittent dry cutting. Grain refinement was found to be an effective means of achieving superior tool performance; the depth of cut had no significant effect on tool performance in intermittent cutting.

S45Cの正面フライス切削時のセラミック工具の損傷

In order to investigate the application of ceramic tools in intermittent cutting, face milling test was conducted on 0.45% carbon steel with several ceramic, carbide and cermet tools. The wear patterns, the wear rates and the tool life were measured and also crater wear was observed precisely with an optical and an electron microscope. Obtained data were analysed to evaluate the wear characteristics of ceramic tools in comparison with those of carbide and cermet tools. Main results obtained are : 1. Ceramic tools are applicable for face milling without tool failure under the selected cutting conditions. 2. Crater wear rate of ceramic tools in face milling is much higher than those of another machining methods. Consequently, 50 μm of maximum crater wear depth is considered to be the suitable tool life criteria from the view point of tool failure. 3. Thermal cracks parallel and normal to the cutting edge are observed in the crater wear region of ceramic tools. Since these cracks in ceramic tools are not so deep as those of carbide and cermet tools, it is considered that they are not essential for the tool failure.

A short-time method for the assessment of the machinability of low carbon free machining steels

The machinability of 14 casts of low carbon free machining steel has been measured by an extensive study of the wear of M2 High Speed Steel tools, based on the International Standards Organisation (I.S.O.) testing procedure. A consideration of the characteristic wear curves of these tools shows that flank wear land width prior to catastrophic failure of the tool decreases with increase in cutting speed or flank wear rate. The proposed short-time test is based on the observed tool wear and tool life characteristics. Essentially the test involves the measurement of a portion of the secondary steady wear stage of an M2 cutting tool which can be extrapolated either numerically or graphically to give the time of catastrophic failure of the tool. The test allows tool life to be predicted to better than ± 10 per cent for this class of workpiece machined with M2 High Speed Steel tools.

Wear Characteristics of Ceramic Tools

Comparative cutting performance tests of two ceramic tools in machining cast iron, AISI-4340, H-11 steel were made, and the wear patterns, wear rates, and tool life data are analyzed to evaluate the performance characteristics of ceramic tools in comparison with that of carbide tools. Also the wear process and mechanism of ceramic tools are investigated by scanning electron microscope techniques and electron microprobe analyses. Some specific causes and mechanism of tool wear are evaluated in relation to the cutting performance data.

円筒形回転切削工具の切削温度と工具摩耗特性

The investigation of cutting temperature and tool wear characteristics of the rotary cutting tool is important to perform its machinerbility analysis. In this paper, cutting temperature is measured by a new temperature measuring equipment. A garter spring devise is used pik up the output signals from thermocouple wires. The tool wear characteristics is also examined. The following conclusions are obtained :1) The cycle of hearting and cooling in cutting temperature due to tip rotation is considerably large. The maximum temperature of the rotating tip is extreamly lower than that of the fixed tip. The differences in cutting temperature are mainly arisen by the increase in cooling effect due to tip rotation and the difference in cutting mechanics.2) The wear of the rotary cutting tool initiate at the corner of the cutting edge and the cutting edge is rounded off as the wear increases. The wear rate of the rotary cutting tool is very small and the tool life increases considerably even in cutting of the Titanium alloy, which is one of refractory materials.

工具摩耗面のマイクロアナラィザによる観察

In order to study the key factors which predominate over the machinability of steel, the fundamentals of the wear phenomena of metal cutting tool was investigated. The electron micro-probe X-ray analyzer was used to uncover the wear characteristics of carbide tools in turning of mild steel and leaded-free-cutting-steel at a cutting speed of 150 m/min. Tool surfaces and the internal sections were subjected to the X-ray micro analysis after 40 minutes of machining.The experimental data shows that only iron and its compounds adhered at the crater of the tool, and aluminum and manganese were detected at the leading land and the trailing surface behind the crater. At the flank wear surfaces, iron, aluminum and manganese coexisted. At the worn surfaces, including the flank wear and crater wear, cobalt was detected with much less intensity than inside the tool material.Concerning the action of lead included in free-cutting-steel, it was concluded that a portion of the lead melted at the tool-chip interface and acted as a lubricant; whereas, the lead particles which were included inside the chip did not melt but acted as notches reducing the toughness of the chip.

The effect of material and geometry on the wear characteristics of cutting tools during face milling

Effects of radial and axial rakes on tool wear characteristics have been explained in terms of the effect of contact length between tool and chip. The microstructure of the tool and of the workpiece material, before and after cutting, has been examined and correlated with the wear characteristics. In the light of the above experiments, tests have been carried out with restricted edge tools and considerable increases in tool life have been obtained.

Machinability of metals and machining costs

In the present work, a comparative study is reported on tool wear characteristics induced by machining two distinctively different types of materials: Vanadis 10 tool steel containing large amounts of MC and M7C3 carbides, and 316L austenitic stainless steel which is nearly free of hard abrasive phases. Tool life tests were conducted using cemented tungsten carbide tools (WC-Co), both uncoated and TiCN-Al2O3 coated. The subsequent wear characterization included scanning electron microscopy and electron backscatter diffraction (EBSD). Examination of worn WC-Co substrates and coatings revealed significantly different wear characteristics after machining the two workpiece materials. Predominantly abrasion-induced wear was revealed by micro-fragmented tool constituents as well as sub-micron sized grooves and ridges on tool substrates and coatings when machining the tool steel. Moreover, EBSD analysis indicated that the tool substrates exhibited significant superficial strains caused by localized plastic deformation during sliding contact of the tools with the carbides of the tool steel. In contrast, during machining of the stainless steel using uncoated tools, the predominantly dissolution-induced wear resulted in WC-Co substrates with smooth surfaces and absence of significant strain. The worn coatings showed signs of spalling of micro-fragments which indicated the dominant contribution of adhesive wear when machining stainless steel.

Performance and wear characteristics of ceramic tools : E. J. Krabacher. Microtecnic (English Edition), v. 13, no. 6, Dec 1959, p. 291–297

Performance and wear characteristics of ceramic tools : E. J. Krabacher. Microtecnic (English Edition), v. 13, no. 6, Dec 1959, p. 291–297