• The Korean Journal of Ceramics
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• v.2 no.4
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• pp.212-215
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• 1996

This paper focuses the strength and wear resistance of CVD diamond films. The strength of free-standing CVD diamond films synthesized by microwave plasm CVD, DC plasma CVD, RF plasma CVD and arc discharge plasma jet CVD has been measured by three-point bending test. The wear resistance of CVD diamod films has been evaluated by the pin-on-disk type testing. diamond films coated on the base of sintered tungsten carbide pin by hot filament CVD have been rubbed with a sintered diamond disk in muddy water. Volume removed wear of CVD diamond has been compared with stellite, WC alloy and bearing steel.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.653-657
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• 2000

Machining performance in hard turning of hardened AISI M2 steel has been studied. Ceramic tools were used in the cutting tests without coolants and workpiece was prepared by heat treatment to increase its hardness up to Rc 60. Cutting state parameters such as cutting forces, temperature, and tool wear were measured in the experiments and effects of tool wear on cutting states were investigated.

• Journal of Power System Engineering
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• v.10 no.2
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• pp.93-98
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• 2006

Metal matrix composites(MMCs) reinforced with ceramic particulates are receiving increasing attention because their high specific strength, low coefficient of thermal expansion and excellent wear resistance. Especially, Al-based composites(AMCs) have been widely applied for the aerospace and automotive industries. Such composites are mainly fabricated by the cast, powder metallurgy and infiltration process. In this study, SiC particulate reinforced Al-based composites were fabricated by thermal spray process and their wear behavior were investigated. Composites with different spray parameter were fabricated by using flame spray apparatus. Microstructure and wear behavior of the composites were observed by scanning electron microscope(SEM) and electron probe micro-analysis(EPMA).

• Proceedings of the Korean Ceranic Society Conference
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• 2003.10a
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• pp.20.1-20.1
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• 2003

• Hip & pelvis
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• v.30 no.4
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• pp.276-281
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• 2018

Pseudotumors are not uncommon complications after total hip arthroplasty (THA) and may occur due to differences in bearing surfaces of the head and the liner ranging from soft to hard articulation. The most common causes of pseudotumors are foreign-body reaction, hypersensitivity and wear debris. The spectrum of pseudotumor presentation following THA varies greatly-from completely asymptomatic to clear implant failure. We report a case of pseudo-tumor formation with acetabular cup aseptic loosening after revision ceramic-on-metal hip arthroplasty. The patient described herein underwent pseudotumor excision and re-revision complex arthroplasty using a trabecular metal shell and buttress with ceramic-on-polyethylene THA. Surgeons should be aware of the possibility of a pseudotumor when dealing with revisions to help prevent rapid progression of cup loosening and implant failure, and should intervene early to avoid complex arthroplasty procedures.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.12
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• pp.1253-1258
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• 2013

Ceramic particles as polishing abrasives are often used in a magnetic abrasive polishing process because they have strong wear resistance. Non-ferromagnetic ceramic abrasives should be mixed with ferromagnetic iron particles for controlling the mixture within a magnetic brush during the polishing process. This study describes the application of the ceramic particles for the magnetic abrasive polishing. The distribution of the magnetic abrasives attached on a tool varies with magnetic flux density and tool rotational speed. From the correlation between abrasive adhesion ratio in the tool and surface roughness produced on a workpiece, practical polishing conditions can be determined. A step-over for polishing a large sized workpiece is able to be selected by a S curve, and an ultrasonic vibration assisted MAP produces a better surface roughness and increases a polishing efficiency.

• Design & Manufacturing
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• v.14 no.3
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• pp.50-56
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• 2020

Ceramic tile is widely used as a floor or interior decoration of buildings. The main processes are raw material blending, molding, drying, firing, etc., and since dimensional and quality stability are very important, they are generally molded by a dry press method. In ceramic tile molds, there is a liner that can be easily replaced in case of wear. The liner is constantly abrasion due to a continuous pressing process during tile forming, and it is required to be replaced every certain period. Even in the liner, use a wear-resistant fitting material only in areas where wear is concentrated. However, there was a risk that the fitting material was applied to large-sized tile molding due to problems such as damage to the molding machine and decrease in productivity when detached during the actual tile molding process due to weak fitting strength with the liner. Therefore, in this study, thermal-structural analysis for fitting tolerance analysis and structural analysis for fitting force analysis were performed for the shrink fit process of the fitting material.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.363-364
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• 2002

Although the factors that cause the failure of orthopedic implants were not clearly determined, it was reported that the shapes of wear debris affect the tribological behavior of artificial implant. Many researches were conducted to examine the wear mechanism by debris but the role of debris shape in inflammatory reaction remains unclear. To observe the debris shape by addition of reinforcement, carbon nanotubes ( CNTs ) were added to ultra high molecular weight polyethylene ( UHMWPE ) to investigate the reinforcement effect of CNTs. CNTs which have a diameter of about 10-50 nm, while their length is about 3-5 nm were produced by the catalytic decomposition of the acetylene gas using a tube furnace. Plate on disc type wear test were performed to evaluate the tribological performance of UHMWPE composites reinforced with CNTs in lubricating condition ( bovine serum ). The wear losses of CNT added UHMWPE in bovine serum were significantly reduced. Worn surface and wear debris of UHMWPE with CNTs and without CNTs were compared to investigate the reinforcement effect of CNT on tribological behavior.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.1
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• pp.142-149
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• 1997

Ceramic-coated anilox roll for printing is resistant to corrosion and wear, and hence has enhanced life and quality. Laser engraving is used typically for machining holes to store ink in this roll. Since engraved hole size and shape are directly related to laser processing parameters, it is necessary to know the rela- tionships among these parameters. In this study, the parameters for engraving of ;oasma sprayed ceramic coatings with Nd:YAG laser were studied. Relationships between hole shape and processing parameters were analyzed. Cr$_{2}$O$_{3}$ceramic was found to be most suitable for Nd:YAG laser engraving. It was found that hole depth can be increased by using higher energy pulses. Effect of using different assistant gases was small to the final results. For better results, it was suggested to use a very stable laser with shorter pulses and higher pulse energy.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.365-366
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• 2002

The sliding wear behavior of ultra high molecular weight polyethylene (UHMWPE) was examined on a novel low temperature degradation-free zirconia/alumina composite material and conventional alumina and zirconia ceramics used for femoral head in total hip joint replacement. The wear of UHMWPE pins against these ceramic disks was evaluated by performing linear reciprocal sliding and repeat pass rotational sliding tests for one million cycles in bovine serum. The weight loss of polyethylene against the novel low temperature degradation-free zirconia/alumina composite disks was much less than those against conventional ceramics for all tests. The mean weight loss of the polyethylene pins was more io the linear reciprocal sliding test than in the repeal pass rotational sliding lest for all kinds of disk materials. Neither the coherent transfer film nor the surface damage was observed on the surface of the novel zirconia/alumina composite disks during the test. The observed r,'stilts indicated that the wear of the polyethylene was closely related to contacting materials and kinematic motions. In conclusion, the novel zirconia/alumina composite leads the least wear of polyethylene among the tested ceramics and demonstrates the potential as lhe alternative materials for femoral head in total hip joint replacement.