In this study, SCM440 alloys are investigated to research the effect of wear resistance. For this purpose, three wear factors which are friction force, wear loss and coefficient of friction applied to test wear-resistance. For the wear test, ball-on-disk was used to assess the variation of wear characteristics. Lastly, the coefficient of wear was calculated by using the Archard's wear equation in SCM440 alloys. The applied normal load was fixed at 30N in all test. The test results showed that SCM440 alloy's Vickers hardness average value is near 671.4Hv, the friction force is 4.11N through the Ball-on-disk test, the coefficient of friction and the wear loss are 0.431 and 0.080 respectively. Finally, Archard’s wear value of SCM440 alloys could be shown approximately 0.1514.
In this study, the effect of wear resistance was investigated in Al 7075 alloys. For this purpose, three wear factor which are wear loss, coefficient of friction and friction forec applied to test wear-resistance. Wear test of ball-on-disk has been performed using steel balls to determine the variation of wear characteristics. Finally, the coefficient of wear was calculated by the Archard wear equation in Al 7075 alloys.
The aim of this study is to investigate the effect of wear resistance with 3D printing of DLP(Digital Light Processing). For this purpose, three wear factor which are wear loss, coefficient of friction and friction force applied to test wear-resistance. Wear test of ball-on-disk has been performed using steel balls to determine the variation of wear characteristics. Finally, the coefficient of wear was calculated by the Archard wear equation with 3D printing of DLP.
The effects of coating parameters were investigated in wear resistance coatings of Diamalloy-406 on Inconel 718 to obtain an optimum coating condition by high velocity oxy-fuel spraying. The coating parameters, the flow rates of source gases (hydrogen and oxygen), the powder feed rate, and the spray distance, were designed by the Taguchi method. The optimal conditions were determined: oxygen flow rate 34 FRM, hydrogen flow rate 57 FRM, powder feed rate 35 g/min, and spray distance 7 inch. Friction coefficients of the coating and the substrate decreased with an increasing sliding surface temperature from 25 oC to 450 oC. The friction coefficient of Diamalloy-4006 coating decreased as the sliding surface temperature increased from 0.43 ± 0.01 at 25 oC to 0.29 ± 0.01 at 450 oC. The wear trace and wear depth of the coating were smaller than the substrate at all temperatures tested. The relationship between spray parameters and wear resistance was discussed extensively, based on the measured roughness, hardness, and porosity in each coating.
This study investigated the microstructure and wear resistance property of HPHT (high pressure high temperature) sintered PDC (polycrystalline diamond compact) in accordance with initial molding pressure. After quantifying an identical amount of diamond powder, the powder was inserted in top of WC-Co sintered material, and molded under four different pressure conditions (50, 100, 150, 200 kgf/cm2). The obtained diamond compact underwent sintering in high pressure, high temperature conditions. In the case of the 50 kgf/cm2 initial molding pressure condition, cracks were formed on the surface of PDC. On the other hand, PDCs obtained from 100~200 kgf/cm2 initial molding pressure conditions showed a meticulous structure. As molding pressure increased, low Co composition within PDC was detected. A wear resistance test was performed on the PDC, and the 200 kgf/cm2 condition PDC showed the highest wear resistance property.
Materials design and processing development proposed in this study, aims at contributing to high wear resistant and friction characteristics. To find wear resistant and friction with inner elbow pipe, it is needed hardness and frictional condition test to be capable of supplying with high Cr casting steel. The result of HTV(heat treatment in vacuum) shows that hardness increased with increasing Cr content in % carbide phase. It was about 7∼10% of hardness improvement compared to original casting elbow pipe. This behavior of the hardness of Cr casting steel was explained by the types of chemical bonds that hold atoms together in Cr carbide phase. Through the friction coefficient and wear loss test, with the increasing of Cr wt% reduction in the coefficient of friction and wear loss.
The types, properties, and processes for wear resistance are reviewed from the viewpoints of material properties, metallurgy, and tribology. Though materials such as ceramics and polymers are used as the wear resistances materials to provide various useful properties, they can offer excellent corrosion and wear resistances as well as mechanical, physical and chemical properties when combined with metal materials. This paper presents, first of all, the concept of surface, kinds of wear resistances and methods based on the characteristics of surface. For that reason classifies wear resistances followed by each surface modification. This, combined with numerous sophisticated wear resistances processes recently developed, makes them the choice of modifications in a large number of applications. This review has been written with an emphasis on wear resistance consisting materials as opposed to metals, ceramics and polymers. It is hoped that this review will serve as a useful source for literature survey as well as an introduction to the subject of wear resistance with materials.
도로표지용 도료의 품질기준은 KS M 6080의 품질기준을 만족하는 제품들의 경우에도 시공 후 일정기간이 경과한 후에는 도료 자체의 부착력 문제로 교통량 증가에 따른 자동차 차륜에 의한 도료 자체의 마모 손실에 의하여 재귀반사 기능을 부여하는 유리알의 마모 및 탈리로 시인성이 급격히 저하되고 있다. 이에 따른 야간 교통 사고율 증가와 동시에 추가 교통 안전을 위한 부가 보완시공으로 안전시설 제비용이 직접비용으로 유발되고 있으며, 직접비용보다 추가공사로 인한 교통체증으로 사회간접 비용이 증가되고 있다. 특히, 차선의 품질 규격이 KS M 6080 제품에 만족한다 하더라도 빗물의 수막(水膜)에 의한 유리알의 굴절율 차로 재귀반사기능을 하는 차선 도료용 유리알의 기능을 발휘하지 못하여 운전자의 시인성은 열악함을 알 수 있다. 따라서, 국외에서 많이 사용되고 있는 마모성이 우수한 수용성 차선도료, 고성능 융착식 도료, 상온경화형 도료를 도입하여 성능을 비교 검토하였다. 본 연구에서는 차선재료의 내구성 향상을 위해 EN 1436규격에 의한 내마모성 시험을 수용성, 융착식, 상온경화형 도료에 실시하여, 재귀반사도 성능이 우수한 차선재료의 적용 가능성을 확인하였다.
We investigated tribological characteristics of diamond-like carbon (DLC) in a condition with carbon nanotube (CNT) content of 1wt% in aqueous solution. Si-DLC films were deposited by radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) process on Al6061 aluminum alloy. In this study, the deposition of DLC films was carried out in vacuum with a chamber pressure of 10-5 to 10-3 Torr achieved by mechanical pump followed by turbo molecular pump. The surface adsorbed oxygen on the Aluminum substrates was removed by passing Ar gas for 10 minutes. The RF power was maintained at 500W throughout the experiment. A buffer layer of HMDSO was deposited on the substrate to improve the adhesion of DLC coating. At this point CH4 gas was introduced in the chamber using gas flow controller and DLC coating was deposited on the buffer layer along with HMDSO for 50 min. The thickness of 1 μm was obtained for DLC films on aluminum substrates The tribological properties of as synthesized DLC films were analyzed by wear test in the presence of dry air, water and lubricant such as CNT ink.
Cubic boron nitride (c-BN) is a promising material for use in many potential applications because of its outstanding physical properties such as high thermal stability, high abrasive wear resistance, and super hardness. Even though 316L austenitic stainless steel (STS) has poor wear resistance causing it to be toxic in the body due to wear and material chips, 316L STS has been used for implant biomaterials in orthopedics due to its good corrosion resistance and mechanical properties. Therefore, in the present study, c-BN films with a B4C layer were applied to a 316L STS specimen in order to improve its wear resistance. The deposition of the c-BN films was performed using an r.f. (13.56 MHz) magnetron sputtering system with a B4C target. The coating layers were characterized using XPS and SEM, and the mechanical properties were investigated using a nanoindenter. The friction coefficient of the c-BN coated 316L STS steel was obtained using a pin-on-disk according to the ASTM G163-99. The thickness of the obtained c-BN and B4C were about 220 nm and 630 nm, respectively. The high resolution XPS spectra analysis of B1s and N1s revealed that the c-BN film was mainly composed of sp3 BN bonds. The hardness and elastic modulus of the c-BN measured by the nanoindenter were 46.8 GPa and 345.7 GPa, respectively. The friction coefficient of the c-BN coated 316L STS was decreased from 3.5 to 1.6. The wear property of the c-BN coated 316L STS was enhanced by a factor of two.
Thermal spray coating process has proven to be effective at producing hard, dense, wear resistance coatings on the relatively mild substrates. Among several spraying techniques, HVOF (High Velocity Oxygen Fuel) and plasma coating processes, which are preferentially used for the wear resistance application such as capstans, have been applied in this study. The effects of pre-treatment, it-process and post-treatment parameters on the wear and mechanical properties of WC+12%Co, Cr3C2 and Al2O3 powder coatings have been investigated and correlated with the microstructures. The results indicated that the carbide coating was more preferable to the oxide coatings and the post-treatments consisting of vacuum annealing and sealing on carbide coatings led to significant improvements in wear resistance, adhesive strength and coating phase stabilization over the other processing techniques in this application.
Cu-20wt.%W 복합재료를 800˚C에서 1000˚C의 소결온도에서 15MPa과 30MPa의 소결압력으로 30분과 60분 동안 유지하여 진공가압소결하였다. 진공가압소결로 제조한 결과 일반적인 소결공정에 비해 높은 밀도와 경도값의 상승 및 내마모성이 향상되었다. 그런데, 15MPa의 소결압력에서 Cu-W의 미세조직은 W이 부분적으로 불균일하게 군집한 것을 관찰할 수 있다. 이러한 결과는 구리와 텅스텐간의 상호 불고용성과 소결시 소결압력의 차이의 의한 효과라 생각된다.