• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2000.11a
• /
• pp.898-901
• /
• 2000

It is known that Si3N4 ceramic insert has less hardness than Al2O3 ceramic insert. But Si3N4 ceramic insert has not only high toughness and strength but also low thermal expansion coefficient, which makes it has longer tool life under thermal stress condition. In this study, commercial Si3N4 ceramic insert and home-made SiC-Si3N4 ceramic insert which has different sintering time and chemical composition is tested under various cutting conditions. The experimental result is compared in terms of tool life and cutting force. Generally, As the cutting speed and the feed rate increased, the cutting force and the flank wear increased too. The performance of SiC-Si3N4 ceramic insert shows the possibility to be a new ceramic tool.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2003.06a
• /
• pp.1772-1775
• /
• 2003

The stiffness of multi-articulated industrial robots is very weak, because their structure is an articulated type with some links and joints. Thus it is known that cutting processes for metals are not accepted in machine shop well, but they have a lot of merits for cutting processes, for example. drilling, tapping. and engraving etc., because of the characteristics of their high degree of freedom. The temptation of cutting aluminium was carried out to investigate the feasibility and the limitations or constrains for cutting metals on them. First the mode shapes of 6-axes FANUC welding robot were taken and analysed, and next the cutting processes were practically carried out on it. The results of study were found out to show the feasibility of cutting processes at end-milling under 6mm of tool diameter. as well as to have some limitations and constrains, for examples, surface roughness and feed rate, depth of cut, cutting force etc..

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2000.05a
• /
• pp.934-938
• /
• 2000

Built-up edge affects the surface integrity of the machined surface and tool wear. Tool geometry and cutting conditions are very important factors to remove BUE. In this paper, we optimized the geometry of the metal slitting saw .1nd cutting conditions to remove BUE by the experiment. In general, the metal slitting saw is plain milling cutter with thickness less of a 3/16 inch. This is used for cutting workpiece where high dimensional accuracy and surface finish are necessary. The experiment was planned with Taguchi method that is based on the orthogonal array of design factors(coating, rake angle, number of tooth, cutting speed, feed rate). Response table was made by the value of the surface roughness, the optimized tool geometry and cutting conditions through response table could be determined. In addition. the relative effect of factors were identified by the variance analysis. filially. coating and cutting speed turned out important factors.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.17 no.11
• /
• pp.2664-2675
• /
• 1993

In this paper, the effects of chip breaker configuration on cutting forces for various cutting conditions are investigated and a method for predicting cutting forces effectively for chip breaker insert in milling is described. Based on the shear plane model and the relevant equations already existing for the relation among the parameters, the method makes use of the analytic geometric approach considering the configuration of cutting too by a 3-dimensional coordinate transformation matrix. The groove type chip breaker insert is modeled to be a double rake insert, represented by the first radial rake angle, the second radial rake angle and the length of land, and the program analyzing the cutting forces is developed. The program capability is verified by comparing the results with the experimental ones for a single cutter; and in case of primary cutting forces, the results of simulation and experiments agree very well showing 2%~16.7% difference within the feed rate range investigated.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 1999.10a
• /
• pp.257-262
• /
• 1999

On End Milling Process predict the cutting force is important. Dynamics the shear stress is the main parameter influencing the energy requirement in machining. It is well known that a nonzero force is obtained when cutting forces measured at different feed rates but otherwise constant cutting conditions are extrapolated to zero feed rate. In this paper, the cutting force measured in end-milling is compared with the simulated force models. The result show that stress measured in cutting is consistent with that stresses predicted.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1996.11a
• /
• pp.31-35
• /
• 1996

The cross section of the circular rod type workpiece to be cut in the band saw machine is variable at every moment in the sawing process. When the cutting feed rate is fixed to the constant speed, the cutting edges of the band saw teeth are also variabl eat any moment, so this causes the wear of the land saw teeth and the deterioration of the quality in the surface roughness. In this study, to work out this kind of problem basically, the mean cutting force of a tooth in the band saw was estimated by using the workpiece which was smaller than the interval of each tooth, i.e. band saw pitch, in the thickness. Then the static cutting forces were predicted by appling the mean cutting forces referred above to the mechanistic cutting force model which were analyzed through the geometric profile of a band saw tooth.

• Journal of the Korean Society for Heat Treatment
• /
• v.7 no.3
• /
• 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.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.22 no.11
• /
• pp.1106-1112
• /
• 2012

This paper deal with a technique for monitoring machining conditions by measuring the vibration of cutting forces at milling machining. The vibrations of cutting forces in milling process were measured and analyzed to be related with processing parameters. The magnitude of cutting force is linearly proportional to the feed rate and cutting depth, and frequency of cutting force is linearly proportional to the rotating speed. Wired and wireless communication methods were applied in transmitting the measured vibration signals and the two methods were compared. The magnitude of the vibration signals transmitted by the wireless communication method was similar to that transmitted by the wired communication method.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.10 no.5
• /
• pp.124-129
• /
• 2001

The experimental study was the cutting characteristics of non-ferrous metals. The experimental apparatus was used the turning machine and diamond tool. This aimed at lading the optimal cutting conditions by measuring surface farm and roughness. Used non-ferrous metals were aluminum, brass and oxygen-free copper. As well, according to changing cutting conditions such as feed rate by measuring cutting farce and surface roughness and according to cutting conditions the non-ferrous metals studied about cutting properties.

• Journal of the Korean Society for Precision Engineering
• /
• v.22 no.5 s.170
• /
• pp.167-174
• /
• 2005

High-speed machining is one of the most effective technologies to improve productivity Because of the high speed and high feed rate, high-speed machining can give great advantages for the machining of dies and molds. This paper describes on the analysis and evaluation of cutting force in high-speed machining. Cutter rotation directions, slope directions, spindle revolution and depth of cut are control factors for cutting force. The effect of the control factors on cutting force is investigated for the high speed machining of STD11.