• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.1
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• pp.85-91
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• 2013

The machinability of wear-resistible tungsten carbides and the tool wear behavior in machining of V30 and V50 tungsten carbides using PCD (Poly Crystalline Diamond) cutting tool was investigated to understand machining characteristics. This material is one of the difficult-to-cut materials in present, but their usage has been already broadened to every commercial applications such as mining tools, and impact resistant tools etc. Summary of the results are as follows. (1) Tool wear progression of PCD tools in turning of wear-resistible tungsten carbides were observed specially fast in primary cutting distance within 10m. (2) Three components of cutting resistance in this research were different in balance from the ordinary cutting such as that cutting of steel or cast iron. Those were expressed large value by order of thrust force, principal force, feed force. (3) If presume from viewpoint of high efficient cutting within this research, a proper cutting speed was 15m/min and a proper feed rate was 0.1mm/rev. In this case, it was found that the tool life of PCD tool was cutting distance until 230m approximately. (4) In cutting of wear-resistible tungsten carbides such as V30 and V50, it was recognized that the tool wear rate of V30 was very fast as compared with V50. (5) When the depth of cut was 0.1mm, there was no influence of the feed rate on the feed force. And the feed force tended to decrease as the cutting distance was long, because the tool was worn and the tool edge retreated. (6) It was observed that the tungsten carbides were adhered to the flank.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.10
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• pp.74-81
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• 2003

This paper describes that the micro-cutting of WC-Co using PCD (Polycrystalline Diamond) and PcBN (Polycrystalline Cubic Boron Nitride) cutting tools are performed with SEM(Scanning Electron Microscope) direct observation method. The purpose of this study is to present reasonable cutting conditions to obtain precise finished surface and machining efficiency. Summary of the results are shown below: (1) The thrust cutting forces tend to increase more than the principal forces as the depth of cut and the cuttlllg speed are increased preferably on orthogonal microcutting. (2) The tool wear in the flank face was formed larger than that in the rake face on orthogonal micro cutting. (3) The wear appearance for PCD tools is abraded by hard WC particles of the work materials, which lead diamond grain to be detached from the bond.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.12
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• pp.47-54
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• 2008

Hard turning process can be defined as a single-point machining process carried out on "hard" materials. The process is intended to replace or limit traditional grinding operations that are expensive, environmentally unfriendly, and inflexible. The purpose of this study is to achieve a systematic understanding of machining characteristics and the effects of machining parameters on cutting force, tool wear shape and chip formation by the outer cutting of a kind of wear resistant tungsten carbide V30. Hard turning experiments were carried out on this alloy using the PCD (Poly Crystalline Diamond), cBN (cubic Boron Nitride) and PcBN (Polycrystalline cubic Boron Nitride) cutting tools. The PcBN and the usual cBN tools were used to be compare with the PCD tool and the dry turning was carried out. The PcBN is attractive as the tool material which replaces the PCD. The tool wear width and cutting force were measured, and the worn tool and chip were observed. The difference of the tool wear mechanism among the three tool materials was investigated.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.12
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• pp.68-75
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• 2000

This paper presents the construction of an ultra-precision machining system and machining experiments using the developed system. The system is composed of air bearing system, granite bed, air pad, and linear feeding mechanism. The cutting conditions have great effect on the surface quality in ultra-precision machining. the ultra-precision machining is mainly processed by several ${\mu}{\textrm}{m}$ depth of cut and feed rate. For this, tools with sharper cutting edge and less tool wear are needed. To satisfy these requirement, diamond is generally used as a tool material for ultra-precision machining. In order to evaluate the cutting characteristics of the PCD and MCD tools on the aluminum alloy, the machining experiments performed using the developed system.

• The Korean Journal of Ceramics
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• v.2 no.4
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• pp.203-211
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• 1996

CVD diamond tools are becoming more widely used in industry as an economic alternative to polycrystalline diamond (PCD) for machining non-ferrous and non-metallic materials. Although CVD diamond-sheet tools have been on the market for several years, diamond-coated carbide inserts have become available only recently, with the successful resolution of long-standing adhesion problems. Diamond coating morphology on the rake surface of the tool affects chip formation favorably, whereas a microscopically rough, faceted morphology on the flank surface of the tool produces a rough workpiece finish. Workpiece finish can be improved by using a coated tool with a larger nose radius. The tool life provided by diamond-coated tools(~30 $\mu\textrm{m}$ thick) can meet or exceed that of PCD tools, depending on the characteristics of the workpiece material. When using diamond-coated carbide tools in milling, a sharp-edged PCD tool should be used in the wiper position of the cutter to minimize workpiece roughness and burr formation.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.9
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• pp.55-62
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• 2003

This paper investigates the micro-cutting of cemented carbides using PCD (polycrystalline diamond) and PCBN (polycrystalline cubic boron nitride) cutting tools are performed with SEM direct observation method. The purpose of this study is to make clear the cutting mechanism of cemented carbides and the fracture of WC particles at the plastic deformation zone in orthogonal micro-cutting. And also to achieve systematic understanding, the effect of machining parameter on chip formation and machined surface was studied, including cutting speed, depth of cut and various tool rake angle. Summary of the results are shown below. (1) Three type of chip formation process have been proposed by the results of the direct observation in orthogonal micro-cutting of cemented carbide materials. (2) From the whole observation of chip formation, primary WC particles are crushed and/or fine grained in the shearing deformation zone. A part of them are observed to collide directly with a cutting edge of tool by following the micro-cutting. (3) Surface finish, surface morphology and surface integrity is good to obtain by cutting with PCD cutting tool compared with PCBN. (4) The machined surface has the best quality near the low cutting speed of 10${\mu}m$/sec with a cutting depth of 10 ${\mu}m$ using 0$^\circ$ rake angle and 3$^\circ$ flank angle in this condition, but it was found that excessively low speed, for example the extent of 1 ${\mu}m$/sec, is not good enough to select for various reason.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1052-1053
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• 2006

Aluminum-based composites reinforced with various amounts of $\alpha-Si_3N_4$ were produced by powder metallurgy (P/M). The machinability properties of $MMC_s$ were determined by means of cutting forces and surface roughness. Machining tests were carried out by using PCD and K10 tools. Increasing of $Si_3N_4$ volume fraction in the matrix resulted in a decrease of the surface roughness and turning forces. PCD cutting tools showed better cutting performance than K10 tools.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.3
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• pp.41-47
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• 2012

Surface roughness is widely used as an index for processing degree of accuracy. Recently, regression analysis to predict the machining results are actively used to characterize a cutting operations. In the past, diamond machining had been used for ultra precision cutting operation, but now industrial diamond tools like PCD(Polycrystaline Diamond) has been widely used in ultraprecision machining of nonferrous metals. In this study, the authors focus on the effect of PCD tool property on the surface roughness of different types of aluminum alloy after cutting process by CNC operated lathe. Based on the regression analysis approach on a surface roughness data obtained by experiment, predictive analysis of surface roughness is effective to achieve better surface quality.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.6
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• pp.69-74
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• 2012

Surface roughness is widely used as an index for processing degree of accuracy. Recently, regression analysis to predict the machining results are actively used to characterize a cutting operations. In the past, diamond machining had been used for ultra precision cutting operation, but now industrial diamond tools like PCD(Polycrystalline Diamond) have been widely used in ultraprecision machining of nonferrous metals. In this study, the authors focus on the effect of PCD tool property on the surface roughness of Al5083 aluminum alloy after cutting process by CNC operated lathe. Based on the regression analysis approach on a surface roughness data obtained by experiment, predictive analysis of surface roughness is effective to achieve better surface quality.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.3
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• pp.284-291
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• 2013

Micro cutting of titanium alloy by polycrystalline diamond (PCD) tools was studied. Micro electro discharge machining (MEDM) was used to fabricate customized micro shaping tools from PCD blank. The tool was used to machine micro grooves on Ti alloy and the effects of depth of cut and machining length on tool wear, burr and surface roughness were studied. The shaping tool has cutting edge of a few ${\mu}m$. The crater size of the tool surface was increased with increasing capacitance of EDM machining conditions, which was used to control the surface roughness of the machined micro grooves.