Types Of Tool Wear Research Articles

Cutting force, tool wear and surface finish in drilling metal matrix composites

In this paper the evolution of the cutting force, tool wear and surface finish, measured when drilling the metal matrix composite A356/20/SiCp-T6, is presented. The experimental work was developed through the continuous measurement of the torque with an appropriate piezoelectric dynamometer and the results were used to derive the cutting power (ranging from 0.1 to 0.4 kW) and the specific cutting pressure, K s (1700-3500 N/mm2). The tool wear type was identified and its evolution with cutting time was measured for different sets of cutting conditions, using polycrystalline diamond drills. The holes' surface finish was evaluated and very good results, exceeding standard values for drilling, were obtained ( R a between 0.25 and 1.2 μm).

Tool wear in cutting plastic — abrasion or erosion?

Tools used to cut, blank and perforate plastics do not seem to wear like one might expect. Cutting edges do not round and loose sharpness as do tools used to cut, blank and perforate metals. A die hole will develop a crater that abuts the periphery of the hole. The crater can have a depth of several micrometers and a width of about a millimeter. The same type of material removal pattern occurs on the end of flat-ended punches. The tool edges maintain sharpness because of this serendipitous material removal. What is producing this wear? Is it simple abrasion from hard phases in the plastic that is being punched or is it erosion from relative motion of the plastic product as it is compressed by the punch? This question was addressed in laboratory experiments conducted in a small punch press. A spring-loaded hemisphere (to simulate the punch) impacted a polished steel counterface (the die) with sheet plastic between the two. The spring-loaded hemisphere produced lateral movement of the plastic on the polished metal or cemented carbide counterface. Fresh plastic material is interspersed between the simulated punch and die for each press stroke. Damage to the counterface was assessed after 10 6 “punches” using profilometry and microscopy. The test results suggest that the predominating mechanism of punch and die wear in finishing cellulosic and thermoplastic polyester webs is erosion by relative motion of the product. The relative motion is caused by elastic deflection of the plastic as it is compressed. The product is behaving like a fluid and material removal is produced by mechanical interaction of a fluid with a solid surface, as required by the definition of erosion. It is proposed that this testing technique be used to assess the type of tool wear that can be anticipated from new plastic products.

Cutting temperature of ceramic tools in high speed machining of difficult-to-cut materials

This paper deals with an experimental and analytical investigation into the different factors which influence the temperature distribution on Al 2O 3TiC ceramic tool rake face during machining of difficult-to-cut materials, such as case hardened AISI 1552 steel (60–65 Rc) and nickel-based superalloys (e.g. Inconel 718). The temperature distribution was predicted first using the finite element analysis. Temperature measurements on the tool rake face using a thermocouple based technique were performed and the results were verified using the finite element analysis. Experiments were then performed to study the effect of cutting parameters, different tool geometries, tool conditions, and workpiece materials on the cutting edge temperatures. Results presented in this paper indicate that for turning case hardened steel, increasing the cutting speed, feted, and depth of cut will increase the cutting edge temperature. On the other hand, increasing the tool nose radius, and angle of approach reduces the cutting edge temperature, while increasing the width of the tool chamfer will slightly increase the cutting ege temperature. As for the negative rake angle, it was found that there is an optimum value of rake angle where the cutting edge temperature was minimum. For the Inconel 718 material, it was found that the cutting edge temperature reached a minimum at a speed of 510 m/min, and feed of 1.25 mm/rev. However, the effect of the depth of cut and tool nose radius was almost the same as that determined in the turning of case hardened steel. It was also observed in turning Inconel 718 with ceramic tools that, cutting forces and different types of tool wear were reduced with increasing the feed.

Ion implantation of cutting tools

This paper treats, in general, different wear mechanisms of metal cutting tools. Almost all physicomechanical properties of the tool material responsible for its wear resistance are shown to be changed under ion beam irradiation. Some practical recommendations on developing ion implantation technology for cutting tools, depending on the predominant type of tool wear, are given.

インコネル７１８材加工におけるＣＢＮ工具の摩耗特性

Cutting performance of CBN tool for the turning of nickel based superalloy (Inconel 718) which is known as one of the difficult to machine materials has been investigated. It was clarified through the microscopic observation of tool-tip after cutting that adhering of the workpiece material to the tool tip occurred and the adhesion affected significantly on the tool life. The type of tool wear varied with cutting speed. Reaction between the workpiece and tool materials was also investigated through a simulated experiment in which both materials were attached with clump and heated up to 1 473 K. Then, the vicinity of the reaction couple was examined carefully by EPMA EDX and AES. Mutual diffusion between the binder phase of the CBN tool and workpiece was observed. Apparently, it could be concluded that such kind of material transfer promoted the tool wear.

High speed steel tool wear studies in machining of glass-fibre-reinforced plastics

Today fibre-reinforced plastics (FRP) occupy an important place as high performance engineering materials. Although in most of the fabrication processes used for glass-fibre-reinforced plastics (GFRP) machining is avoided, sometimes the machining of an FRP product to achieve the required shape and dimensional tolerance cannot be avoided. In the present work, the face turning of filament-wound GFRP tubes using high speed steel (HSS) tool bits is studied. This paper examines the mechanism of material removal during GFRP machining and the type of tool wear in HSS tools with different cobalt contents. The mechanism of tool wear is explained with the help of scanning electron micrographs of worn out tool faces.

Study on Drilling of Reinforced Plastics (GFRP and CFRP) : Relation between Tool Material and Wear Behavior

In recent years, the reinforced plastics (GFRP, CFRP and others) are used in a wide field of manufacturing industry. With an increase of the demand for such composite materials, the need to drill these products is increasing rapidly. This paper deals with drilling of GFRP and CFRP, using high speed steel (SKH9) and cemented carbode (KOl. PlO and ultra-fine grain) drills. Comparison of four drills is done by investigating tool wear pattern, flank wear width and cutting forces. A new type of tool wear which should be referred to as "combing wear" was found in drilling of CFRP. In addition, it was found that KOl has the highest wear resistance, FG shows the second highest and the wear of high speed steel drill is remarkably larger than that of carbide drills.

The practical estimation of tool wear in turning

The effects of various factors on the three main types of tool wear were investigated experimentally. A fourth type of tool wear, nose wear, is included in flank wear and the experimental results show that it is larger than crater wear. Several important results on the effects of the factors investigated are obtained.

炭素鋼の切削における工具寿命について

The relations between tool life, cutting temperature, mechanical properties of the work materials are experimentally analyzed.Annealed and normalized plain carbon steels, of which carbon contents are varied from 0.15 % to 0.55 % are turned with carbide tools.For the aforementioned purpose, only normal or regular type of tool wear is taken into consideration for the tool life criteria.The major findings are as follows.(1) Under the fixed condition of work material and tool, the tool life can be defined by one variable function of cutting temperature.(2) Under the fixed cutting condition of cutting speed, feed per revolution and depth of cut, the tool life is closely related with Brinell hardness HB, and ultimate strain of the shear test γu.(3) The relationships between tool life equation and mechanical properties of the work materials are as follows.V·Tn exp (δ·f) dβ=Cn∝HB0.23·γu0.22δ∝HB-1.01·γu-0.29C∝HB-1·36·γu-0.145where, V= cutting speed, m/min, f=feed per revolution, mm/rev, d=depth of cut, mm.Because, it is very difficult to vary said variables independently each other, they are not independent from a physical point of view.However, the relationships can be derived mathematically, by means of a unique analytical method.

切削作業標準設定に関する研究(第2報)

For the right selection of machining conditions and carbide grades, close investigations of the tool wear and the wear process are essential. The object of this paper is to offer some informations about the tool wear in machining 18-8 stainless steel. Various types of tool wear are presented anddiscussed on the basis of wear process. Particularly, the rate of cratering is studied experimentally, introducing the coefficient of the rate of cratering so that reliable evaluations of carbide tools can be achieved as far as cratering is concerned.

Cutting-Fluid Evaluation

Abstract Transfer of radioactive material from a cutting tool to the chips produced in facing the end of a steel tube is used as a means of measuring tool-wear rate. The lathe is operated at commercial feeds and speeds. This technique permits accurate tool-wear evaluation with very short machining time and a consequent small consumption of stock. Protection of personnel against radiation requires simple precautions. Evaluation of a cutting oil may require consideration of the roughness of the cut surface or the cutting temperature in addition to the tool-wear rate. The properties of the material cut influence the type of tool wear experienced and may affect the choice of variables which must be considered in addition to tool-wear rate. Results for typical compound and mineral oils in the machining of both 1015 and 1045 steels are reported.