Abstract:Wear performance of Cu matrix composites prepared by pulsed electric current sintering (PECS) was evaluated by using non-lubricated sliding tests. The studied materials contained cuprite (Cu 2 O), alumina (Al 2 O 3 ), titaniumdiboride (TiB 2 ) or diamond dispersoids in a coarse-grained Cu (c-Cu), submicron-grained Cu (sm-Cu), or nano-grained Cu (nCu) matrix. PECS compacted matrix materials were used as references. The ball-on-flat tests showed strong dependence of the coefficient of friction (CoF), wear rate a… Show more
“….% G1-50 wt.% G2 compositions, by applying the 10 N loads, was recorded. But it has not effect on COF values significantly perhaps in G1-G2 composite due to different roughness the resulted composite did not show the improved COF value [26].…”
Section: Discussionmentioning
confidence: 86%
“…However, probably, the compressive stress extent on the surface of coats has not effect on COF values significantly (G2 and G1) moreover in the case of G1-G2 composite (Fig. 10c) perhaps due to the two different roughness the resulted composite did not show the improved COF value (unlike the wear rate) [26].…”
Two frites with 40 wt.%SiO2-20 wt.%B2O3-17 wt.%Na2O (G1) and 42wt.%SiO2-24wt.%BaO-18 wt.%CoO (G2) compositions were prepared and applied on stainless steel by the slurry method. The samples were heated at 950ºC (G2) and 860ºC (G1). The XRD results revealed the sodium silicate and barium silicate phases as well as almost 770 HV, 543 HV microhardness in G1 and G2 coats respectively. The thermal expansion coefficients were α=10.9×10-6/K(G1) and α=13.31×10-6/K (G2) respectively. According to EDS results the alkaline earth ions (and CoO) migration into the glass- steel interface was occurred in both coats. The dry sliding friction and wear behavior were investigated using a 4mm diameter AISI52100 steel pin on disk geometry under 5,10 and 18 N loads. The average wear rate were w.r: 32 ×10-14(m3/N.m) and w.r:5×10-14(m3/N.m) in G1 and G2 coats. Then two frites were mixed and heat treated at 800ºC with high heating and cooling rate. The resulted composite (G1-G2) shows almost the average wear rate 4×10-14(m3/N.m), while the coefficient friction of G1-G2 composite was not improved significantly.
“….% G1-50 wt.% G2 compositions, by applying the 10 N loads, was recorded. But it has not effect on COF values significantly perhaps in G1-G2 composite due to different roughness the resulted composite did not show the improved COF value [26].…”
Section: Discussionmentioning
confidence: 86%
“…However, probably, the compressive stress extent on the surface of coats has not effect on COF values significantly (G2 and G1) moreover in the case of G1-G2 composite (Fig. 10c) perhaps due to the two different roughness the resulted composite did not show the improved COF value (unlike the wear rate) [26].…”
Two frites with 40 wt.%SiO2-20 wt.%B2O3-17 wt.%Na2O (G1) and 42wt.%SiO2-24wt.%BaO-18 wt.%CoO (G2) compositions were prepared and applied on stainless steel by the slurry method. The samples were heated at 950ºC (G2) and 860ºC (G1). The XRD results revealed the sodium silicate and barium silicate phases as well as almost 770 HV, 543 HV microhardness in G1 and G2 coats respectively. The thermal expansion coefficients were α=10.9×10-6/K(G1) and α=13.31×10-6/K (G2) respectively. According to EDS results the alkaline earth ions (and CoO) migration into the glass- steel interface was occurred in both coats. The dry sliding friction and wear behavior were investigated using a 4mm diameter AISI52100 steel pin on disk geometry under 5,10 and 18 N loads. The average wear rate were w.r: 32 ×10-14(m3/N.m) and w.r:5×10-14(m3/N.m) in G1 and G2 coats. Then two frites were mixed and heat treated at 800ºC with high heating and cooling rate. The resulted composite (G1-G2) shows almost the average wear rate 4×10-14(m3/N.m), while the coefficient friction of G1-G2 composite was not improved significantly.
“…Inherently, harder reinforcement particles withstand the load and act as asperities and reduce the pin-counterface contact area, which result in the reduction of friction coefficient. 49,50 Figure 8.Average friction coefficient values of all specimens at three different applied loads of 10, 20, and 30 N and sliding speed of 0.7 m/s.…”
Section: Resultsmentioning
confidence: 99%
“…Inherently, harder reinforcement particles withstand the load and act as asperities and reduce the pin-counterface contact area, which result in the reduction of friction coefficient. 49,50 FESEM morphologies of the worn out surface is provided in Figure 9, which gives a clear statement of wear that took place in each samples. From Figure 9(a), FESEM morphology gives a clear cut view on the cutting action undergone by the soft copper material due to plastic deformation and wear.…”
In the present study, Cu–3, 6, and 9 wt.% of ZrO2 nanocomposites were prepared by an in situ reactive synthesis of copper nitrate Cu(NO3)2 and zirconium oxychloride ZrOCl2. The structure and characteristics were examined by X-ray diffraction, field emission scanning electron microscopy and transmission electron microscopy. The results showed that the nanosized ZrO2 particles with about 45 nm was successfully formed and dispersed within the copper matrix. The effect of ZrO2 nanoparticles content on relative density, Vickers hardness, specific electrical resistivity, and coefficient of thermal expansion was evaluated. The pin-on-disc test was also performed to determine dry sliding wear behavior of specimens under different wear conditions. Hardness and specific electrical resistivity increased and density of Cu-ZrO2 nanocomposites decreased with increasing amount of ZrO2 in Cu matrix. The coefficient of thermal expansion significantly increased with increasing temperature but decreased with increasing ZrO2. The wear rate and friction coefficient of the developed surface composite was found decreasing with respect to increase in the dispersion of ZrO2. Amongst the copper surface composite, specimen with 9 wt.% of ZrO2 has shown the least wear rate with low coefficient of friction.
“…Due to its particular outer cell electron structure, the application of rare earth is exposed to many research fields such as optics, tribology [7,8], etc. Rare earth oxides are considered to be the ideal sintering addictive because of their high melting points, chemical stability, excellent mechanical, thermal, optical, and electrical properties [9,10]. La 2 O 3 has a unique electronic structure because that was successfully added into the metal to improve the toughness, strength, and tribological properties [11].…”
In the present paper, the effect of La2O3 nanoparticle was studied on the physical and electrochemical properties of Cu/Cu-C contacts. The nanocomposite materials were prepared using different La2O3 contents (1.0-2.0 wt.%) processed by the spark plasma sintering method. The microstructural observations, density, hardness, electrical resistance measurements, and electrochemical behavior characterization were conducted. The results showed that the hardness, electrical resistance, and corrosion resistance of composites increase with the addition of La2O3 nanoparticle.
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