• Polymer(Korea)
• /
• v.29 no.1
• /
• pp.48-53
• /
• 2005

Tire wear is one of the factors that most drivers have concerned and is closely related to the tire life. It is very difficult to predict tire wear because the factors affecting tire wear seem to be very comlicated. Tire wear test should be performed at real conditions for the evaluation of tire wear. In this study, we analyze tire wear according to the severities of test courses by using the dedicated test method, more severe than real driving conditions. In order to simplify the factors affecting tire wear, we define roads’ driving severities to be driving severity numbers, DSNs which are obtained by measuring the lateral accelerations of test courses. And we compared tire wear rates and profiles with DSNs. These test results can provide the tire design guide to meet tire wear performance.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.3 no.4
• /
• pp.17-24
• /
• 2001

Four road tunnels of which the construction conditions were similar were selected in the paper, and laboratory tests and rockmass classification for the tunnels were carried out. And the analysis was performed to find out the correlation between ratio of bit abrasion or drilling parameter and support pattern of tunnel using jumbo drill machine. It was analyzed that there was average abrasion of bit from 11.85% to 3.25% per support patterns of tunnel in four tunnels. Drilling parameter happens to fluctuate according to extent of fracture zone.

• Journal of the Korean Society of Industry Convergence
• /
• v.7 no.4
• /
• pp.369-376
• /
• 2004

It is shown that the rate of wear can be related to on 'index of wear intensity'. Since both upper and lower specimens have used the same hardness values, equivalent hardness of 'index of wear intensity' used the mean hardness value of specimens. This index is derived from the external variables of load, sliding speed and the hardness of the sliding pairs. The wear behavior as the hardness of the sliding elements on the dry wear has been investigated using a disc on disc configuration. The materials of the specimens are used as ten kinds along their hardness. Using experimental data, we figured the relationship between wea rate and index of wear intensity. The result had been derived a newly wear equation in disc on disc wear system.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.17 no.3
• /
• pp.27-33
• /
• 2008

It is shown that the rate of wear can be related to 'index of wear intensity' using a leaf-spring in the disc on disk on wear tests. Since both upper and lower specimens have used the same hardness values, equivalent hardness of 'the index of wear intensity' used the mean hardness value of specimens. This index is derived from the external variables of load, sliding speed and the hardness of the sliding pairs. The wear behavior as the hardness of the sliding elements on the dry wear has been investigated using a disc on disc configuration. The materials of the specimens are used as ten kinds along their hardness. Using experimental data, we figured the relationship between wear rate and index of wear intensity. A newly wear equation had been derived the result using a leaf-spring in disc on disc wear system.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2012.11a
• /
• pp.113-114
• /
• 2012

본 연구는 segment target을 사용하여 unbalanced magnetron sputtering을 활용하여 고 CrZr-Si-N 박막을 합성하고 박막의 미세구조 및 마모 특성을 연구하는데 그 목적이 있다. 박막의 Si 함량을 조절하기 위하여 각 segment target은 Cr,Zr을 일정vol% 유지하며 Si vol%만 변화하여 설계하였다. Si 함량별로 제작된 마모실험 시편의 미세구조는 XRD, FE-SEM, AFM, TEM을 통하여 분석하였으며, ball on disk type의 마모 시험기를 통해 그 마모 특성을 분석하였으며,

• Composites Research
• /
• v.30 no.5
• /
• pp.310-315
• /
• 2017

In this study, we have investigated microstructure, mechanical properties and wear characteristic of aluminum metal matrix composites with a high volume fraction and uniformly dispersed SiC particles which produced by a liquid pressing process. The volume fraction of bimodal SiC/Al7075 composite was 12% higher than that of the monomodal SiC/Al7075 composite and a compressive strength is increased about 200 MPa. As a result of the abrasion test, the wear width and depth of the bimodal SiC/Al7075 composite were $285.1{\mu}m$ and $0.45{\mu}m$, respectively. The coefficient of friction of bimodal SiC/Al7075 was 0.16.

• Journal of the Korean Vacuum Society
• /
• v.7 no.1
• /
• pp.59-65
• /
• 1998

Multi-layer diamond-like carbon (DLC) films were deposited by 13.56 MHz r.f. PACVD method. Multi-layer DLC film was composed of 2.5 $mu extrm{m}$ thick pure DLC filml and 0.2$\mu\textrm{m}$ thick Si incorporated DLC (Si-DLC) film as a surface layer. Tribological behaviors of the multi-layer DLC film were investigated with a ball-on-disk type tribometer in ambient atmosphere using AISI 52100 steel ball. Low friction coefficient (<0.1) period increased with increasing the Si content in the surface Si-DLC film. The wear rate after 44,000 cycles and 158,400 cycles were the $2.5\times10^{-8}\sim1.8\times10^{-7}\textrm{mm}^3$/rev. and $7.1\times10^{-9}\sim1.8\times10^{-8}\textrm{mm}^3$/rev.,respectively. The wear rate of the multi-layer DLC film after 158,400 cycles was about 2 times smaller than that of pure DLC films of 2.7 $\mu\textrm{m}$ thickness. This high wear resistance and low friction coefficient was caused by the formation of Si oxide layer on the wear scar surface, as confirmed by the debris composition analysis. It was further shown that this si oxide debris layer on the wear scar surface is formed again even after removing the debris of the steel ball, which maintain the low friction coefficient between multi-layer DLC films and steel ball.

• Journal of Power System Engineering
• /
• v.15 no.1
• /
• pp.51-56
• /
• 2011

The various process parameters of thermal spray process affects on quality of Ni-based coatings. Thus, there is need to analyze the effect of process parameters on quality of Ni-based coatings. In this paper, the effects of process parameters on hardness and wear rate of Ni-based coatings were investigated using 4 design of experiments. First, the Ni-based coatings were fabricated according to $L_9(3^4)$ orthogonal array. The hardness tests and the wear tests were performed on the Ni-based coatings. The analysis of variance for the hardness and wear rate were carried out. As a results, the acetylene gas flow and the powder feed rate were identified as main factors effected on the hardness and the oxygen gas flow and the acetylene gas flow were identified as main factors effected on the wear rate. The full factorial experiments design with different levels was applied for investigation of effect of these main factors.

• Applied Chemistry for Engineering
• /
• v.17 no.5
• /
• pp.547-551
• /
• 2006

In the reactor following the American standard test method (ASTM) D5757-95 and lab-scale fluidized bed combustor, the attrition characteristics of sand and ash of Korean anthracite were investigated. The attrition characteristics, such as particle size distribution of fly ash, attrition rate, and attrition ratio etc, were studied with variation of gas velocities. The particle attrition of ash was more active than sand which was generally used as a fluidized material and also the attrition index of ash taken by ASTM D5757-95 was 5 times higher than that of sand. The formation of fine particles continuously occurred due to particle attrition with increasing gas velocities. The following equation has been suggested for attrition rate of ash. $$\frac{dW}{dt}=-3.18{\times}10^{-7}(U-U_{mf})W$$.

• Korean Journal of Materials Research
• /
• v.8 no.12
• /
• pp.1138-1145
• /
• 1998

The sliding wear behavior of Ni-base hardfacing alloy, Deloro 50, was investigated at the contact stresses of 15ksi and 30ksi under the various wear environments. In air at room temperature, Deloro 50 showed lower wear resistance than Stellite 6 even at 15ksi due to the occurrence of severe adhesive wear. This seems to be caused by the lower hardness and work- hardening rate of Deloro 50 than those of Stellite 6. In water at room temperature, Deloro 50 showed as good wear resistance as Stellite 6 at 15ksi. It was considered to be due to that water could effectively prevent metal to metal contact through contacting asperities. However, Deloro 50 showed severe adhesive wear at 30ksi in water at room temperature. It seems to be that the water could not suppress adhesion wear at 30ksi. At $300^{\circ}C$ in air, Deloro 50 exhibited higher wear resistance than Stellite 6 even at 30ksi. It was considered that the oxide glaze layers formed on wear surface during sliding, effectively prevented direct metal-to-metal contacts.