• 대한기계학회논문집A
• /
• 제24권3호
• /
• pp.786-793
• /
• 2000

Nylon, Polyacetal and PTFE were studied to gain a better understanding of their tribological behavior. Wear tests were conducted with reciprocating motion under dry sliding conditions. Friction coefficient and specific wear rate were measured as a function of sliding distance. The worn surfaces were examined with a Scanning Electron Microscope(SEM). Polyacetal showed lowest specific wear rates and PTFE exhibited lowest friction coefficient. The dominant wear mechanism found were adhesion and abrasion.

• 한국윤활학회:학술대회논문집
• /
• 한국윤활학회 1999년도 제30회 추계학술대회
• /
• pp.35-41
• /
• 1999

Friction and wear test was performed for nylon, acetal resin, and PTFE(polytetrafluoroethylene) under reciprocating dry sliding conditions against a steel counterpart. Friction coefficient and specific wear rate were analysed as a function of sliding distance and applied load. The worn surfaces of plate and disc specimens were observed using SEM(Scanning Electron Microscopy). The experimental results show that acetal resin exhibited lowest wear rates whereas PTFE possessed lowest friction coefficient. The prominent wear mechanisms found were adhesion and abrasion.

• 한국분말재료학회지
• /
• 제9권2호
• /
• pp.103-109
• /
• 2002

To investigate the fabrication possibility of a polymer particle dispersed metal matrix composite, polytetrafluorothylene (PTFE) particles were incorporated into the Al by the powder metallurgy process. The characteristics of a PTFE/Al composite were evaluated by measuring the density and hardness, and analysis of XRD, FT-Raman and microstructure. And wear properties of these composites were evaluated under the dry wear condition. It was possible to obtain the PTFE particles stably dispersed Al matrix composites by the hot press process at the sintering temperature of $500^{\circ}C$. The wear coefficient of a PTFE/Al compoite decreased with increasing of the volume fraction of PTFE. The wear weight of a PTFE/Al composite increased with increasing of the volume fractionof PTFE in the range of 0~10 vol.%PTFE, and showed maximum value at 10 vol.%PTFE, and then decreased at 20vol.%PTFE.

• Tribology and Lubricants
• /
• 제39권6호
• /
• pp.228-234
• /
• 2023

In this study, reciprocating wear tests are performed on AISI 52100 bearing steel to investigate its tribological behavior in a hexagonal boron nitride (h-BN) water solution. The h-BN-based aqueous lubricant is prepared using an atoxic procedure called ultrasonic sonication in pure water. Ball-on-flat reciprocating sliding experiments are conducted, where the ball is slewed on a fixed flat at 50-㎛ displacement. The lubricating behavior of h-BN is compared with that of deionized (DI) water. Results show that the friction coefficient is higher in h-BN testing than that in DI tests, but the results are equalized as the friction coefficient reaches a stable level. Scanning electron microscopic images reveal significant material loss in the center and mild abrasion on the edge of the wear scar in h-BN tests. However, these effects are minor in DI water situations. The results of energy-dispersive X-ray spectroscopy show that considerable oxidation occurs in the central zone of the wear scar in h-BN cases with strong adhesion and material removal. These findings reveal the importance of determining ideal circumstances that can tolerate material friction and wear.

• Tribology and Lubricants
• /
• 제16권6호
• /
• pp.409-414
• /
• 2000

The friction and wear behaviors of MoS$_2$ coatings were investigated by using a pin and disk type tester. The experiment was conducted by using silicon nitride as pin material and MoS$_2$-on-bearing steel as disk material under different operating conditions that include linear sliding velocities in the range of 22-66 ㎜/sec, normal loads varying from 9.8 N to 29.4 N, corresponding to maximum contact pressures of 1.18-2.83 GPa and atmospheric conditions of high vacuum, medium vacuum, ambient air. The results showed that low friction coefficient of the coating has been identified in high vacuum and that friction coefficient and wear volume increased with increasing normal load. Also at high load conditions, the friction coefficient and wear volume increased with increasing sliding velocity.

• KSTLE International Journal
• /
• 제1권2호
• /
• pp.91-94
• /
• 2000

The friction and wear behavior of MoS$_2$coatings was investigated using a pin and disk type tester. The experiment was conducted with silicon nitride as the pin material and MoS$_2$-on-bearing steel as the disk material under different operating conditions that included linear sliding velocities within a range of 2266 mm/sec, normal loads varying from 9.829.4 N, corresponding to maximum contact pressures of 1.782.83 Gpa, and high vacuum, medium vacuum, and ambient air atmospheric conditions. The results showed a low friction coefficient far the coating in a high vacuum, plus the friction coefficient and wear volume increased with an increased normal load. Furthermore, under high load conditions, the friction coefficient and wear volume also increased with an increased sliding velocity.

• 한국윤활학회:학술대회논문집
• /
• 한국윤활학회 1999년도 제30회 추계학술대회
• /
• pp.94-100
• /
• 1999

The friction and wear behavior of MoS$_2$Coatings were investigated using a pin and disk type tester. The experiment was conducted using silicon nitride as pin material and MoS$_2$-on-bearing steel as disk material under different operating conditions that include linear sliding speeds in the range of 22~66mm/sec, normal loads varying from 9.8~29.4N, corresponding to maximum contact pressure of 1.78~2.830GPa and atmospheric conditions of high vacuum, medium vacuum, ambient air. The results showed that low friction coefficient of the coating has been identified when running in high vacuum and that friction coefficient and wear volume increased with increasing normal load. Also at high load conditions, the friction coefficient and wear volume increased with increasing sliding velocity.

• Carbon letters
• /
• 제12권4호
• /
• pp.249-251
• /
• 2011

Carbon/epoxy woven composites are prominent wear-resistant materials due to the strength, stiffness, and thermal conductivity of carbon fabric. In this study, the effect of oilabsorption on the wear behaviors of carbon/epoxy woven composites was investigated. Wear tests were performed on dry and fully oil-absorbed carbon/epoxy woven composites. The worn surfaces of the test specimens were examined via scanning electron microscopy to investigate the wear mechanisms of oil-absorbed carbon/epoxy woven composites. It was found that the oil absorption rate was 0.14% when the carbon/epoxy woven composites were fully saturated. In addition, the wear properties of the carbon/epoxy woven composites were found to be affected by oilabsorption. Specifically, the friction coefficients of dry and oil-absorbed carbon/epoxy woven composites were 0.25-0.30 and 0.55-0.6, respectively. The wear loss of the oilabsorbed carbon/epoxy woven composites was $3.52{\times}10^{-2}\;cm^3$, while that of the dry carbon/epoxy woven composites was $3.52{\times}10^{-2}\;cm^3$. SEM results revealed that the higher friction coefficient and wear loss of the oil-absorbed carbon/epoxy woven composites can be attributed to the existence of broken and randomly dispersed fibers due to the weak adhesion forces between the carbon fibers and the epoxy matrix.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2008년도 추계학술대회 논문집
• /
• pp.113-114
• /
• 2008

• 한국표면공학회지
• /
• 제36권2호
• /
• pp.116-121
• /
• 2003

Ti-Si-N coating layers were deposited onto WC-Co substrates by a hybrid system of arc ion plating (AIP) and sputtering techniques. The tribological behaviors of Ti-Si-N coating layers with various Si contents were investigated by the dry sliding wear experiments, which were conducted at three different sliding speeds, 0.1, 0.3, 0.5 m/s, against the steel and alumina balls. In the case of steel ball, the average friction coefficient slightly decreased with increasing the sliding speed regardless of Si content due to adhesive wear behavior between coating layer and steel ball. At constant sliding speed, the average friction coefficient decreased with increase of Si content. On the contrary, in the case of alumina ball, the average friction coefficient increased with increasing the sliding speed regardless of Si content, indicating that the abrasive wear behavior was more dominant when the coating layers slide against alumina ball. Through these experimental results, it was found that the tribological behaviors of Ti-Si-N coating layers were effected by factors such as Si content, sliding speed, and kinds of counterpart materials rather than the hardness of coating layer.