• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 춘계학술대회 논문집
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• pp.88-92
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• 2004

We developed a helical type drum with an oblique cutting condition for sawdust machine. The existing drum has an orthogonal cutting(2D) condition considering of saw cutter and wood cutting pattern. Additional disadvantage of this type include big cutting resistance, high cost of cutting power and extreme occurrence of vibrations. To improve this shortcoming, we developed a helical type drum with an oblique cutting(3D) condition, therefore, this type drum decreased the vibration and cutting resistance of sawdust machine, and also improved productivity and sawdust porosity.

• 한국생산제조학회지
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• 제5권3호
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• pp.58-65
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• 1996

This thesis is concerned with the study on the characteristics of the cutting resistance occurring in finish machining of hardened steels such as carbon tool steel and alloy tool steel by a ceramic tool with nose radius. For the purpose, the shape of cutting cross-section made at nose part of the tool was analyzed geometrically and the wear mechanism on the flank face of the ceramic tool is investigated. In order to investigate the characteristics of cutting resistance two categories of cutting conditions are suggested, along with geometrical analysis. One category includes the conventional cutting parameters such as feed and depth of cut, another containing new cutting parameters of thickness of cut and width of cut etc. Thickness of cut width of cut and area of undeformed chip section formed by the condition of engagement between workpiece and cutting tool are determined as the function of feed, depth of cut and nose radius of cutting too, And an effective approach angle is determined by depth of cut and nose radius.

• 한국공작기계학회논문집
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• 제10권5호
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• pp.39-44
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• 2001

In this paper, drill fred mechanism, cutting depth measuring device and sensing buzzer of drill contact were investigated in order to develop the micro-hole drilling machine. Also, measuring device of cutting resistance was developed in order to estimate cutting resistance from change of cutting condition. The results show that extremely-low fled rate(less then $17{\mu}m/S$${\mu}{\textrm}{m}$ /s) can be done and cutting depth can be measured by up to 1${\mu}{\textrm}{m}$ with developed drilling machine. Accordingly we could assemble a very cheap micro-hole drilling machine($\phi$ 0.05~0.5 mm). Also we got the some properties of cutting performance i.e. under the same condition, cutting torque decreases as increase of spindle speed and rapid fled of drill brings about the inferior cutting state under low spindle speed.

• 한국기계가공학회지
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• 제3권4호
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• pp.81-87
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• 2004

The titanium has many superior characteristics such as specific strength, heat resistance, corrosion resistance, organism compatibility, non-magnetic and etc. and their quantity are abundant. This study performed turning operation of Ti-6Al-4V alloy using the TiAlN coated tool which was treated with PVD. Experimental works were also executed to measure cutting force, chip figuration and surface roughness for different cutting conditions. As a result of study, tool wear was serious at the condition over 100m/min of cutting speed. The excellent cutting condition of cutting depth was at 1.0mm.

• 한국기계가공학회지
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• 제19권11호
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• pp.23-28
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• 2020

In general, lithography techniques are applied when machining single-crystal silicon in nanoscale applications; however, these techniques involve low degrees of freedom for the vertical shapes. By applying mechanical techniques to machine silicon, nanopatterns having various types of vertical shapes can be manufactured. In this study, we determined the ductile-brittle machining transition point and analyzed the- variation of the specific cutting resistance within the ductile machining region in nanoscale applications. When brittle fracture occurred during the nanoscale cutting, the depth of cut and cutting force increased and decreased rapidly, respectively. The first point of rapid increase in the depth of cut was defined as the ductile-brittle machining point. Subsequently, the shape of the machining tool was observed using a scanning electron microscope to calibrate the machining area, considering the tip blunting. The specific cutting resistance decreased continuously and converged to a certain value during the nanoscale cutting. The decrease and convergence in the value can be attributed to the decrease in the ratio of the arc length to the area of the machining tool and silicon.

• 대한기계학회논문집
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• 제12권5호
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• pp.1043-1054
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• 1988

본 연구에서는 공구(bite)의 형상에서 상면경사각을 변화시켜 이에 따른 절삭 저항의 3분력을 측정하여 그 값에 대한 합력과 비절삭저항 그리고 거칠기 등 3값을 normalization 과정으로 energy method에 의하여 이들 SM20C 및 SM45C 재료를 구분하 여 각각의 절삭저항과 그 특성을 규명하고져 하였으며 아울러 재료별 최적조건을 찾고 자 한다.

• 오토저널
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• 제14권6호
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• pp.105-112
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• 1992

The turning tests with sintered carbide tools have been conducted on typical high strength SSW2 railway wheel steel and its machinability were examined in terms of the cutting resistance, the roughness of turning surface, the chip disposal and others. Some results obtained in this paper are as follows: (1) The cutting resistance is not affected by the cutting speed (in this paper these were 23-78 m/min). (2) The roughness of finished surface is found to be largely dependent on cutting conditions and tool geometry. (3) There exists the explicit relates between the tool geometry cutting conditions (cutting speed, feedrate, and depth of cut) and independent variables(cutting resistance, surface roughness) are derived.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1551-1554
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• 2005

The Titanium has many superior characteristics Which are specific strength, heat resistance, corrosion resistance, organism compatibility, non-magnetic and etc. and their quantity are abundant. this study performed turning operation of Ti-6Al-4V alloy using the TiAlN Coate Tool which treated PVD (Physical Vapor Deposition). Experimental works are also executed to measure cutting force, chip figuration and surface roughness for different cutting conditions. As a result of study. Tool wear was serious at over 100m/min of cutting speed and cutting condition was excellent at 1.0mm of cutting depth.

• 한국정밀공학회지
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• 제18권4호
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• pp.182-189
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• 2001

TiCN based submicron cermet and similar ISO grad of the conventional cermets with TiCN of different particle size were produced by PM process, and their microstructure, mechanical properties and cutting performance were compared. The microstructure of submicron cermet was more homogeneous and showed much finer microstructure, resulting in better hardness and fracture toughness. The submicron cermet tools achieved excellent cutting performance such as wear resistance and toughness in comparison with two grades of the conventional cermets in millimg test. The relationship between microstrucure, mechanical properties and cutting performance of these cermet tools was discussed. The submicron cermet tools revealed for their potential to wide application range and interrupt cutting because of their superior wear resistance and toughness combinations.

• Elastomers and Composites
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• 제37권2호
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• pp.86-98
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• 2002

본 연구에서는 실리카/카본블랙 혼합사용과 카본블랙 단독 사용의 경우 상온 또는 고온에서의 인장강도(modulus) 및 인열저항성, 내cutting성, 내crack성을 비교 평가하였다. 실리카와 카본블랙의 함량비 및 단계배합 방법을 통해 NR 가황물을 제조하였으며, 충전제의 함량은 60phr로 고정하였고, semi-EV 가황시스템을 적용하여 실험을 실시하였다. 실리카의 분산은 25phr이하일 때 양호하였으며, 실리카/카본블랙의 함량비가 25/35인 경우 인열에너지, 내crack특성, 내cutting특성이 가장 우수하였다. 충전제로써 카본블랙 단독사용과 실리카/카본블랙(25/35) 혼합사용의 경우를 비교해 보면, 열화에 따른 modulus 및 인장강도, 인열에너지는 실리카/카본블랙(25/35)을 사용한 시편이 더 낮은 감소율을 나타내었다. Cutting특성에서는 카본블랙 단독 사용보다는 실리카/카본블랙(25/35) 혼합사용의 경우가 더 높은 cutting 저항성을 나타내었다. 내crack 특성 또한 실리카/카본블랙(25/35)을 혼합사용한 경우가 온도에 따른 더 높은 변형에너지 완화율(Gp)에도 불구하고 더 낮은 크랙성장속도를 나타내었다.