• Journal of the Korean Society for Heat Treatment
• /
• v.18 no.6
• /
• pp.355-361
• /
• 2005

In this study, the effects of the maximum undeformed chip thickness on grinding characteristics of hardened steel in down-grinding have been investigated. The meaured grinding forces become larger as the workpiece velocity increases. The specific energy, e decreases as the maximum undeformed chip thickness increase. When the maximum undeformed chip thickness is the same, the specific energy, e decreases as the grain size increases.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.16 no.2
• /
• pp.30-36
• /
• 2007

In order to estimate the maximum undeformed chip thickness in grinding operation, it is necessary to obtain the successive cutting point spacing. In the past it was obtained by experiments. In this paper, the average successive cutting point spacing has been obtained using the given grinding input conditions and it is possible to estimate the maximum undeformed chip thickness without using any experimentally obtained data. The validity of the proposed analysis has been verified based on two sets of grinding scratch tests using WA and CBN grinding wheels.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2004.10a
• /
• pp.16-21
• /
• 2004

As a new approach to analyze grinding energy, this paper introduces a specific grinding energy model based on the average grain. Using this model, grinding characteristics such as radial and tangential forces, specific grinding energy of SM45C were investigated altering grinding variables such as workpiece velocity(v) and apparent depth of cut(Z) in down-surface grinding. From the experimental results, there is no significant difference between the radial, tangential forces and vertical. horizontal forces because of small contact angle between wheel and workpiece. The specific grinding energy decreases as the maximum undeformed chip thickness increases. But, there is much difference between the specific grinding energies of the existing and the proposed model.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2005.05a
• /
• pp.319-323
• /
• 2005

As a new approach to analyze grinding energy, this paper introduces a specific grinding energy model based on the average grain. Using this model, grinding characteristics such as specific grinding energy of SM45C were investigated with changing variables such as grain size, workpiece velocity(v) and apparent depth of cut(Z) in down-surface grinding. From the experimental results, the specific grinding energy decreases as the maximum undeformed chip thickness increases. And also the specific grinding energy increases as the grit size increases.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.14 no.4
• /
• pp.61-68
• /
• 2005

As a new approach to analyze grinding energy, this paper introduces a specific grinding energy model based on the average grain. Using this model, grinding characteristics such as radial and tangential forces, specific grinding energy of SM45C were investigated with changing grinding variables such as workpiece velocity(v) and apparent depth of cut(Z) in down-surface grinding. From the experimental results, the specific grinding energy decreases as the maximum undeformed chip thickness increases. And there is no significant difference between the specific grinding energies of the existing and the proposed model.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.10a
• /
• pp.1004-1007
• /
• 2005

As a new approach to analyze grinding energy, this paper introduces a specific grinding energy model based on the average grain. Using this model, grinding characteristics such as specific grinding energy of SM45C were investigated with changing variables such as grain size of CBN, workpiece velocity(v) and apparent depth of cut(Z) in down-surface grinding. From the experimental results, the specific grinding energy decreases as the maximum undeformed chip thickness increases.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2006.05a
• /
• pp.227-228
• /
• 2006

In order to calculate the maximum undeformed chip thickness in grinding operation, it is necessary to estimate the successive cutting point spacing. In the past it is obtained by experiments. In this paper, the average successive cutting point spacing has been estimated using the given grinding input conditions.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.21 no.2
• /
• pp.191-195
• /
• 2012

Heavy flint optical glass(SF57HHT) is new material that has extremely high transmittance. Due to brittleness and high hardness, optical glass is one of the most difficult to materials for ultra-precision turning. According to the hypothesis of ductile machining, all materials, regardless of their hardness and brittleness, will undergo transition from brittle to ductile machining region below critical undefromed chip thickness. In this study, cutting test was carried out to evaluate cutting performance of heavy flint glass using ultra-precision machine with single crystal diamond bite. The machined workpiece surface topography, tool wear and surface roughness were examined using AFM and SEM. The experimental results indicate that the machining mode become the brittle mode to ductile mode, when the maximum undeformed chip thinkness is large than critical value. Tool wear mainly occurs on the flank face and its wear mechanism is dominated by abrasion. This study demonstrates the feasibility of SF57HHT by diamond turning.