• 열처리공학회지
• /
• 제7권3호
• /
• pp.199-205
• /
• 1994

The fracture characteristics and tool life of ceramics and WC, CBN cutting tool when turning heat treated steel STD11($H_RC$ 60) were investigated experimentally to clarify the machinability and optimum tool materials in cutting of difficult-to-cut material with high hardness. Forthermore, the behaviors of the tool wear and failure were examined with regard to cutting force. The hardened steel wore the cutting tool edge rapidily and increased the cutting forces, especially radial force. The tool was worn by the abrasive action. Flank Weat of $Al_2O_3-TiC$ ceramic and WC tool become relatively large and CBN & $Al_2O_3$, ceramic tool had a long life among the tool materials tested. The tool fracture patterns were just like minor cutting wear, flank wear, crater wear, notch wear, chipping. Flank wear rate was accelerated by occurrence of chipping. During the proceeding of machining, it was possible to foresee the catastrophic fracture of tool by abrupt increase of radial force.

• 소성∙가공
• /
• 제15권1호
• /
• pp.57-64
• /
• 2006

High speed milling experiment on the hardened mold steel (CALMAX at hardness of HRC 55) is carried out using small diameter ball endmills. Tool lift and wear characteristics under the various machining parameters are investigated Effect of dynamic runout on the wear of the tool is also studied. For most of the cases, catastrophic chipping of tool edge is not observed and uniformly distributed wear on the flank surface of the tool is obtained. It is found that lower rate of tool wear is obtained as the cutting speed is increased. Also, high pick feed rate is found to be more favorable in terms of the tool wear and material removal rate.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2005년도 금형가공,미세가공,플라스틱가공 공동 심포지엄
• /
• pp.114-120
• /
• 2005

High speed milling experiment on the hardened mold steel (CALMAX at hardness of HRc 55) is carried out using small diameter ball endmill. Tool lift and wear characteristics under the various machining parameters are investigated. Effect of dynamic runout on the wear of the tool is also studied. For most of the cases, catastrophic chipping of tool edge is not observed and uniformly distributed wear on the flank surface of the tool is obtained. It is found that lower rate of tool wear is obtained as the cutting speed is increased. Also, high pick feed rate is found to be more favorable in terms of tool wear and material removal rate.

• 한국윤활학회:학술대회논문집
• /
• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
• /
• pp.237-239
• /
• 2002

The effect of particle sizes of the metal matrix composites containing 10 wt.%SiCp was investigated with using various tools. The results showed that tool life decreased considerably with increasing particle size and cutting speed. The wear resistance of TiC-coated tools was considerably higher than that of the other tools. It was observed that abrasive wear was the main responsible mechanism for wear of the tool thermal cracks were at high speed while a built-edge formation was also evident at lower speed.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 2000년도 춘계학술대회논문집 - 한국공작기계학회
• /
• pp.39-45
• /
• 2000

This paper describes the fundamental investigations on the in-process monitoring techniques focused on Acoustic Emission(AE) based on analytical method. Experiments were conducted on a CNC lathe using conventional carbide insert tools under various cutting conditions. As the result of this study a suggestion is given about the multi-purpose use of AE-signals detected with a single sensor for the monitoring of tool wear, built-up edge and chatter vibration in turning process.

• 대한기계학회논문집
• /
• 제19권3호
• /
• pp.705-712
• /
• 1995

The wear characteristics and wear mechanisms in TiN coating deposited on high speed steel and alloy tool steel by ion plating were investigated. Pin on V-block wear tester was used for a wear test method. The specimen was composed of three kinds of high speed steel and alloy tool steel which had different hardness by changing the heat treating condition. Three kinds of coating thickness were also applied to each specimen. Microscopic observation of worn surfaces was made by SEM. The scratch test of coating surface by the ion plating showed that critical load to break the coating interface was greater than 50N. The critical load increased with both substrate hardness and coating thickness. The wear resistance of TiN coated high speed steel became 10 times greater than that of non-coated ones. SEM observation showed that leading edge of contact was compressive and trailing edge was under maximum tensile stress and then surface cracking broke out perpendicular to sliding direction.

• 오토저널
• /
• 제9권5호
• /
• pp.49-56
• /
• 1987

This paper is a study on the effect of the cutting speed on the tool wear in turning of the glass fiber reinforced plastics. The wear behavior of cutting tool is studied by means of turning, changing the cutting speed and feed in the wide range. Moreover, the theoretical model applicable to the cutting speed of wide range is analysed. The main results obtained are as follows: The relation between the tool wear and the cutting speed is divided into three range in case of the constant cutting distance. 1) At the low cutting speed, the tool wear is independent of the cutting speed, but dependent mainly on the contact length between tool and glass fiber(lst range). 2) At the high cutting speed, the tool wear is independent of the contact length, and dependent on the cutting speed only(2nd range). The tool wear increases in proportion to the cutting speed. 3) At the higher cutting speed than the speed in the 2nd range, the tool wear is independent both of the cutting speed and the contact length(3rd range). 4) In the 3rd range, tool flank wear is constant and is observed that only the wear of cutting edge increases.

• 한국정밀공학회지
• /
• 제15권9호
• /
• pp.135-144
• /
• 1998

High speed machining is a key issue in die and mold manufacturing recently. Even though this technology has great potential of high productivity. tool wear accelerated by high cutting speed to the hardened materials is other barrier. In this research, we attempted to reduce tool wear by considering tool inclination angle between tool and workpiece. The boundary lines describing machined sculptured surfaces were represented by both of cutting envelop condition and the geometric relationship of successive tool paths. Chip cross section, and cutting length could be obtained from the calculated cutting edge and the rotational engagement angle. From the simulation results, machining inclination angle of tool of $15^\circ$ was good enough from the point of tool wear and cutting force, and this value was verified through the cutting experiment of high speed ball end milling.

• 한국기계가공학회지
• /
• 제20권9호
• /
• pp.48-56
• /
• 2021

Tungsten carbide (WC) circular saws have been widely used to cut plywood. Recently, expensive polycrystalline diamond (PCD) were adopted to extend the tool life of circular saws. This study developed a PCD-WC combination circular saw and compared its performance with that of existing WC and PCD saws. Flank wear of WC saw blades and edge chipping of rectangular PCD was observed during the experiments. The PCD-WC saw replaced half of the chamfered teeth with PCD and applied tough WC for all rectangular teeth. In the experiments, edge chipping was not observed in rectangular WC teeth and the flank wear of chamfered teeth was decreased compared with that of conventional circular saws.

• 한국정밀공학회지
• /
• 제19권2호
• /
• pp.228-236
• /
• 2002

In this study, the carbon steels, SM20C were machined with the tungsten carbide tipped circular saw to clarify the cutting-off characteristics in terms of tool wear. The results show that an improved performance in view of both the tool wear and the cutting efficiency was obtained by using oil base cutting fluid at the cutting speed of 100m/min with the feed of 0.06mm/tooth. The rake angle of 10$^{\circ}$ , clearance angle of 8$^{\circ}$ , nose radius of R0.1mm, and end cutting edge champer of 0.1mm$\times$25$^{\circ}$ are believed as the best tool geometries. The tool wear decreases due to using the saw of the disk of STS5 and the tool material of P30.