The Experts below are selected from a list of 231 Experts worldwide ranked by ideXlab platform
Kenneth Holmberg - One of the best experts on this subject based on the ideXlab platform.
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the impact of tribology on energy use and co2 emission globally and in combustion engine and electric cars
Tribology International, 2019Co-Authors: Kenneth Holmberg, A ErdemirAbstract:Abstract Growing concerns over energy and environmental sustainability have lately sparked worldwide interest in more efficient and cleaner transportation systems and industrial activities. Friction roughly consumes one-fifth of all energy used worldwide. One-third of all energy used in transportation goes to Overcome Friction. At the same time, the fruits of decades of dedicated research on all-electric vehicles powered by advanced batteries are paving the way toward a much cleaner and sustainable transportation future. In this article, we provide a short overview of what are the energy efficiency and environmental impacts of current transportation, industrial, and residential systems and how much of that efficiency is adversely affected by Friction and wear losses in moving mechanical parts and components. We also touch upon recent advances in new materials, lubricants, and design changes that could reduce energy losses by 18–40%, mainly resulting from Friction and wear. The savings would be up to 8.7% of the total global energy use and 1.4% of the gross national products (GNP). Finally, we calculate the energy consumption and Friction losses in battery-powered electric passenger cars and show the benefit of electric cars where the total energy use is in average 3.4 times lower compared to combustion engine powered cars. The CO2 emissions are 4.5 times higher for a combustion engine car compared to an electric car when the electricity comes from renewable energy sources. Moving from fossil to renewable energy sources may cut down the energy losses due to Friction in energy production by more than 60%.
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Influence of tribology on global energy consumption, costs and emissions
Friction, 2017Co-Authors: Kenneth Holmberg, Ali ErdemirAbstract:Calculations of the impact of Friction and wear on energy consumption, economic expenditure, and CO 2 emissions are presented on a global scale. This impact study covers the four main energy consuming sectors: transportation, manufacturing, power generation, and residential. Previously published four case studies on passenger cars, trucks and buses, paper machines and the mining industry were included in our detailed calculations as reference data in our current analyses. The following can be concluded: – In total, ~23% (119 EJ) of the world's total energy consumption originates from tribological contacts. Of that 20% (103 EJ) is used to Overcome Friction and 3% (16 EJ) is used to remanufacture worn parts and spare equipment due to wear and wear-related failures. – By taking advantage of the new surface, materials, and lubrication technologies for Friction reduction and wear protection in vehicles, machinery and other equipment worldwide, energy losses due to Friction and wear could potentially be reduced by 40% in the long term (15 years)and by 18% in the short term (8 years). On global scale, these savings would amount to 1.4% of the GDP annually and 8.7% of the total energy consumption in the long term. – The largest short term energy savings are envisioned in transportation (25%) and in the power generation (20%) while the potential savings in the manufacturing and residential sectors are estimated to be ~10%. In the longer terms, the savings would be 55%, 40%, 25%, and 20%, respectively. – Implementing advanced tribological technologies can also reduce the CO 2 emissions globally by as much as 1,460 MtCO 2 and result in 450,000 million Euros cost savings in the short term. In the longer term, the reduction can be 3,140 MtCO 2 and the cost savings 970,000 million Euros. Fifty years ago, wear and wear-related failures were a major concern for UK industry and their mitigation was considered to be the major contributor to potential economic savings by as much as 95% in ten years by the development and deployment of new tribological solutions. The corresponding estimated savings are today still of the same orders but the calculated contribution to cost reduction is about 74% by Friction reduction and to 26% from better wear protection. Overall, wear appears to be more critical than Friction as it may result in catastrophic failures and operational breakdowns that can adversely impact productivity and hence cost.
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global impact of Friction on energy consumption economy and environment
FME Transactions, 2015Co-Authors: Kenneth Holmberg, A ErdemirAbstract:Energy is a key resource for our society today and will be crucial for our sustainability in the future. A considerable amount of energy is consumed to Overcome Friction, especially in the transportation, industrial, and power-generation sectors, and major economic losses are also due to wear of products and components and their replacement. Jost [1] concluded that studies carried out in several industrial countries indicate that 1.0 to 1.4 % of the gross national product can be saved by introducing better tribological practices, requiring investment in research and development at a rate of one in 50 of the savings obtainable. Today, considerable effort is being devoted to producing increasingly more energy efficient vehicles and machines, not only for economic reasons, but also to help meet the requirements for reduced CO2 emissions arising from the Kyoto Protocol on climate change. A major source of CO2 emissions are cars and trucks. Transportation consumes about 20 % of the global primary energy and accounts for about 18 % of the total anthropogenic greenhouse gas emissions [2,3]. In this paper we summarize our studies for calculating the global energy consumption due to Friction and potential savings from Friction reduction in transportation and in industry [4-6]. We first focused our attention on passenger cars for two reasons: passenger cars form a major consumer of energy and also generate a considerable part of the greenhouse gas emissions. The other reason was that the energy use in passenger cars has been largely studied on the systemto-component level. The present study is based on the current set of technical solutions for passenger cars, trucks, buses and advanced industrial processing machinery here represented by paper machines, while the effects of expected changes, future trends, and predictions in this set are not included.
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global energy consumption due to Friction in trucks and buses
Tribology International, 2014Co-Authors: Kenneth Holmberg, Peter Andersson, Nilsolof Nylund, Kari Makela, A ErdemirAbstract:Abstract In this paper, we report the global fuel energy consumption in heavy-duty road vehicles due to Friction in engines, transmissions, tires, auxiliary equipment, and brakes. Four categories of vehicle, representing an average of the global fleet of heavy vehicles, were studied: single-unit trucks, truck and trailer combinations, city buses, and coaches. Friction losses in tribocontacts were estimated by drawing upon the literature on prevailing contact mechanics and lubrication mechanisms. Coefficients of Friction in the tribocontacts were estimated based on available information in the literature for four cases: (1) the average vehicle in use today, (2) a vehicle with today׳s best commercial tribological technology, (3) a vehicle with today׳s most advanced technology based upon recent research and development, and (4) a vehicle with the best futuristic technology forecasted in the next 12 years. The following conclusions were reached: • In heavy duty vehicles, 33% of the fuel energy is used to Overcome Friction in the engine, transmission, tires, auxiliary equipment, and brakes. The parasitic Frictional losses, with braking Friction excluded, are 26% of the fuel energy. In total, 34% of the fuel energy is used to move the vehicle. • Worldwide, 180,000 million liters of fuel was used in 2012 to Overcome Friction in heavy duty vehicles. This equals 6.5 million TJ/a; hence, reduction in Frictional losses can provide significant benefits in fuel economy. A reduction in Friction results in a 2.5 times improvement in fuel economy, as exhaust and cooling losses are reduced as well. • Globally a single-unit truck uses on average 1500 l of diesel fuel per year to Overcome Friction losses; a truck and trailer combination, 12,500 l; a city bus, 12,700 l; and a coach, 7100 l. • By taking advantage of new technology for Friction reduction in heavy duty vehicles, Friction losses could be reduced by 14% in the short term (4 to 8 years) and by 37% in the long term (8 to 12 years). In the short term, this would annually equal worldwide savings of 105,000 million euros, 75,000 million liters of diesel fuel, and a CO2 emission reduction of 200 million tones. In the long term, the annual benefit would be 280,000 million euros, 200,000 million liters of fuel, and a CO2 emission reduction of 530 million tonnes. • Hybridization and electrification are expected to penetrate only certain niches of the heavy-duty vehicle sector. In the case of city buses and delivery trucks, hybridization can cut fuel consumption by 25% to 30%, but there is little to gain in the case of coaches and long-haul trucks. Downsizing the internal combustion engine and using recuperative braking energy can also reduce Friction losses. • Electrification is best suited for city buses and delivery trucks. The energy used to Overcome Friction in electric vehicles is estimated to be less than half of that of conventional diesel vehicles. Potential new remedies to reduce Friction in heavy duty vehicles include the use of advanced low-Friction coatings and surface texturing technology on sliding, rolling, and reciprocating engine and transmission components, new low-viscosity and low-shear lubricants and additives, and new tire designs that reduce rolling Friction.
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global energy consumption due to Friction in paper machines
Tribology International, 2013Co-Authors: Kenneth Holmberg, Roope Siilasto, Tarja Laitinen, Peter Andersson, Ari JasbergAbstract:Abstract Calculations on the global energy consumption used to Overcome Friction in paper machines in terms of Friction in motors, transmissions, pumps, blowers, agitators, pipes and the roll systems are presented. The following was concluded: – The energy consumed to Overcome Friction in a paper mill is in the range 15–25%. – Globally there were 8525 paper and paperboard machines in operation in 2012. One paper machine uses on an average 140 TJ of electrical energy per year. Of this 32% is consumed to Overcome Friction, 36% is used for the paper production and mass transportation and 32% is other losses. – The Friction losses in an average paper machine are in total 44.8 TJ per year, and they are distributed as 32% due to Friction in water-lubricated sliding in seals, doctor blades and fabric/support contacts, 23% due to Friction in elastohydrodynamic rolling contacts, 22% due to Friction in elastohydrodynamic rolling–sliding contacts, 15% due to Friction in oil-lubricated seals and 8% due to Friction in hydrodynamically lubricated contacts. – Worldwide 105,000 GWh electrical power was used in 2009 to Overcome Friction in paper machines. This equals to 381,000 TJ of annual energy consumption. – By taking advantage of new technology for Friction reduction in paper machines, Friction losses could be reduced by 11% in the short term (about 10 years), and by 23.6% in the long term (20–25 years). This would equal to annual worldwide economic savings of 2000 million euros and 4200 million euros; electricity savings of 36,000 and 78,000 GWh; and CO2 emission reduction of 10.6 million and 22.7 million tonnes. Potential mechanisms to reduce Friction in paper machines include the use of low-Friction and highly durable coatings, surface engineering including texturing, low-viscosity and low-shear lubricants and fluids, novel additives, new materials in seals, doctorblades and fabrics, as well as new designs.
A Erdemir - One of the best experts on this subject based on the ideXlab platform.
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the impact of tribology on energy use and co2 emission globally and in combustion engine and electric cars
Tribology International, 2019Co-Authors: Kenneth Holmberg, A ErdemirAbstract:Abstract Growing concerns over energy and environmental sustainability have lately sparked worldwide interest in more efficient and cleaner transportation systems and industrial activities. Friction roughly consumes one-fifth of all energy used worldwide. One-third of all energy used in transportation goes to Overcome Friction. At the same time, the fruits of decades of dedicated research on all-electric vehicles powered by advanced batteries are paving the way toward a much cleaner and sustainable transportation future. In this article, we provide a short overview of what are the energy efficiency and environmental impacts of current transportation, industrial, and residential systems and how much of that efficiency is adversely affected by Friction and wear losses in moving mechanical parts and components. We also touch upon recent advances in new materials, lubricants, and design changes that could reduce energy losses by 18–40%, mainly resulting from Friction and wear. The savings would be up to 8.7% of the total global energy use and 1.4% of the gross national products (GNP). Finally, we calculate the energy consumption and Friction losses in battery-powered electric passenger cars and show the benefit of electric cars where the total energy use is in average 3.4 times lower compared to combustion engine powered cars. The CO2 emissions are 4.5 times higher for a combustion engine car compared to an electric car when the electricity comes from renewable energy sources. Moving from fossil to renewable energy sources may cut down the energy losses due to Friction in energy production by more than 60%.
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global impact of Friction on energy consumption economy and environment
FME Transactions, 2015Co-Authors: Kenneth Holmberg, A ErdemirAbstract:Energy is a key resource for our society today and will be crucial for our sustainability in the future. A considerable amount of energy is consumed to Overcome Friction, especially in the transportation, industrial, and power-generation sectors, and major economic losses are also due to wear of products and components and their replacement. Jost [1] concluded that studies carried out in several industrial countries indicate that 1.0 to 1.4 % of the gross national product can be saved by introducing better tribological practices, requiring investment in research and development at a rate of one in 50 of the savings obtainable. Today, considerable effort is being devoted to producing increasingly more energy efficient vehicles and machines, not only for economic reasons, but also to help meet the requirements for reduced CO2 emissions arising from the Kyoto Protocol on climate change. A major source of CO2 emissions are cars and trucks. Transportation consumes about 20 % of the global primary energy and accounts for about 18 % of the total anthropogenic greenhouse gas emissions [2,3]. In this paper we summarize our studies for calculating the global energy consumption due to Friction and potential savings from Friction reduction in transportation and in industry [4-6]. We first focused our attention on passenger cars for two reasons: passenger cars form a major consumer of energy and also generate a considerable part of the greenhouse gas emissions. The other reason was that the energy use in passenger cars has been largely studied on the systemto-component level. The present study is based on the current set of technical solutions for passenger cars, trucks, buses and advanced industrial processing machinery here represented by paper machines, while the effects of expected changes, future trends, and predictions in this set are not included.
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global energy consumption due to Friction in trucks and buses
Tribology International, 2014Co-Authors: Kenneth Holmberg, Peter Andersson, Nilsolof Nylund, Kari Makela, A ErdemirAbstract:Abstract In this paper, we report the global fuel energy consumption in heavy-duty road vehicles due to Friction in engines, transmissions, tires, auxiliary equipment, and brakes. Four categories of vehicle, representing an average of the global fleet of heavy vehicles, were studied: single-unit trucks, truck and trailer combinations, city buses, and coaches. Friction losses in tribocontacts were estimated by drawing upon the literature on prevailing contact mechanics and lubrication mechanisms. Coefficients of Friction in the tribocontacts were estimated based on available information in the literature for four cases: (1) the average vehicle in use today, (2) a vehicle with today׳s best commercial tribological technology, (3) a vehicle with today׳s most advanced technology based upon recent research and development, and (4) a vehicle with the best futuristic technology forecasted in the next 12 years. The following conclusions were reached: • In heavy duty vehicles, 33% of the fuel energy is used to Overcome Friction in the engine, transmission, tires, auxiliary equipment, and brakes. The parasitic Frictional losses, with braking Friction excluded, are 26% of the fuel energy. In total, 34% of the fuel energy is used to move the vehicle. • Worldwide, 180,000 million liters of fuel was used in 2012 to Overcome Friction in heavy duty vehicles. This equals 6.5 million TJ/a; hence, reduction in Frictional losses can provide significant benefits in fuel economy. A reduction in Friction results in a 2.5 times improvement in fuel economy, as exhaust and cooling losses are reduced as well. • Globally a single-unit truck uses on average 1500 l of diesel fuel per year to Overcome Friction losses; a truck and trailer combination, 12,500 l; a city bus, 12,700 l; and a coach, 7100 l. • By taking advantage of new technology for Friction reduction in heavy duty vehicles, Friction losses could be reduced by 14% in the short term (4 to 8 years) and by 37% in the long term (8 to 12 years). In the short term, this would annually equal worldwide savings of 105,000 million euros, 75,000 million liters of diesel fuel, and a CO2 emission reduction of 200 million tones. In the long term, the annual benefit would be 280,000 million euros, 200,000 million liters of fuel, and a CO2 emission reduction of 530 million tonnes. • Hybridization and electrification are expected to penetrate only certain niches of the heavy-duty vehicle sector. In the case of city buses and delivery trucks, hybridization can cut fuel consumption by 25% to 30%, but there is little to gain in the case of coaches and long-haul trucks. Downsizing the internal combustion engine and using recuperative braking energy can also reduce Friction losses. • Electrification is best suited for city buses and delivery trucks. The energy used to Overcome Friction in electric vehicles is estimated to be less than half of that of conventional diesel vehicles. Potential new remedies to reduce Friction in heavy duty vehicles include the use of advanced low-Friction coatings and surface texturing technology on sliding, rolling, and reciprocating engine and transmission components, new low-viscosity and low-shear lubricants and additives, and new tire designs that reduce rolling Friction.
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global energy consumption due to Friction in passenger cars
Tribology International, 2012Co-Authors: Kenneth Holmberg, Peter Andersson, A ErdemirAbstract:Abstract This study presents calculations on the global fuel energy consumption used to Overcome Friction in passenger cars in terms of Friction in the engine, transmission, tires, and brakes. Friction in tribocontacts was estimated according to prevailing contact mechanisms such as elastohydrodynamic, hydrodynamic, mixed, and boundary lubrication. Coefficients of Friction in the tribocontacts were estimated based on available information in the literature on the average passenger car in use today, a car with today’s advanced commercial tribological technology, a car with today’s best advanced technology based upon recent research and development, and a car with the best technology forecasted in the next 10 years. The following conclusions were reached: • In passenger cars, one-third of the fuel energy is used to Overcome Friction in the engine, transmission, tires, and brakes. The direct Frictional losses, with braking Friction excluded, are 28% of the fuel energy. In total, 21.5% of the fuel energy is used to move the car. • Worldwide, 208,000 million liters of fuel (gasoline and diesel) was used in 2009 to Overcome Friction in passenger cars. This equals 360 million tonne oil equivalent per year (Mtoe/a) or 7.3 million TJ/a. Reductions in Frictional losses will lead to a threefold improvement in fuel economy as it will reduce both the exhaust and cooling losses also at the same ratio. • Globally, one passenger car uses on average of 340 l of fuel per year to Overcome Friction, which would cost 510 euros according to the average European gas price in 2011 and corresponds to an average driving distance of 13,000 km/a. • By taking advantage of new technology for Friction reduction in passenger cars, Friction losses could be reduced by 18% in the short term (5–10 years) and by 61% in the long term (15–25 years). This would equal worldwide economic savings of 174,000 million euros and 576,000 million euros, respectively; fuel savings of 117,000 million and 385,000 million liters, respectively; and CO 2 emission reduction of 290 million and 960 million tonnes, respectively. • The Friction-related energy losses in an electric car are estimated to be only about half those of an internal combustion passenger car. Potential actions to reduce Friction in passenger cars include the use of advanced coatings and surface texturing technology on engine and transmission components, new low-viscosity and low-shear lubricants and additives, and tire designs that reduce rolling Friction.
Xiyao Liu - One of the best experts on this subject based on the ideXlab platform.
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understanding wear interface evolution to Overcome Friction and restrain wear of tial 10 wt ag composite
Advanced Engineering Materials, 2018Co-Authors: Kang Yang, Xiyao LiuAbstract:The main objective of this paper is to study wear interface evolution for analyzing the of Friction and wear property of TiAl–10 wt%Ag composite. The results show that the Friction coefficient and wear rate of TiAl–10 wt%Ag rapidly reduce at 0–25 min and rhythmically fluctuate at 25–60 min. TiAl–10 wt%Ag at 60–240 min obtains low Friction and less wear. It is concluded that silver with the low shearing strength of about 125 MPa shows the eminent plastic deformation on wear interface. It effectively reduces Friction resistance and material loss, cause TiAl–10 wt%Ag to obtain low Friction coefficient, and less wear rate at 0–25 min. Increased silver content, reduces oxide content, and varies wear mechanisms cause the repeating variation of Friction resistance and material loss, which results in the rhythmical fluctuation of Friction coefficient and wear rate at 25–60 min. High silver contents exist on smooth wear interfaces, exhibit the eminent plastic deformation to lower Friction and reduce wear. TiAl–10 wt%Ag obtains the low Friction and less wear at 60–240 min.
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Understanding Wear Interface Evolution to Overcome Friction and Restrain Wear of TiAl–10 wt%Ag Composite
Advanced Engineering Materials, 2017Co-Authors: Kang Yang, Xiyao Liu, He QiangAbstract:The main objective of this paper is to study wear interface evolution for analyzing the of Friction and wear property of TiAl–10 wt%Ag composite. The results show that the Friction coefficient and wear rate of TiAl–10 wt%Ag rapidly reduce at 0–25 min and rhythmically fluctuate at 25–60 min. TiAl–10 wt%Ag at 60–240 min obtains low Friction and less wear. It is concluded that silver with the low shearing strength of about 125 MPa shows the eminent plastic deformation on wear interface. It effectively reduces Friction resistance and material loss, cause TiAl–10 wt%Ag to obtain low Friction coefficient, and less wear rate at 0–25 min. Increased silver content, reduces oxide content, and varies wear mechanisms cause the repeating variation of Friction resistance and material loss, which results in the rhythmical fluctuation of Friction coefficient and wear rate at 25–60 min. High silver contents exist on smooth wear interfaces, exhibit the eminent plastic deformation to lower Friction and reduce wear. TiAl–10 wt%Ag obtains the low Friction and less wear at 60–240 min.
Nobuo Nakahara - One of the best experts on this subject based on the ideXlab platform.
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Thermal performance and pressure drop of rock beds with large storage materials
Solar Energy, 1991Co-Authors: Kazunobu Sagara, Nobuo NakaharaAbstract:Abstract In air-based solar heating systems, the fan power needed to Overcome Friction loss in rock beds can reduce the benefit of the system. The system performance of rock beds with large-sized storage materials that have comparably low Friction loss is studied. A theoretical model of the heat transfer process within the rock bed is developed for large storage materials. In this model, the temperature within the materials is assumed to be distributed quadratically and symmetrically at their center. The relationship between the model parameter and the air flow rate was derived from experimental measurements for some large materials as well as the pressure drop through the bed. The energy performance of heat pump solar systems with rock beds of various storage materials are studied by the computer simulation under Japanese winter weather conditions. It is concluded that the possibility exists for some large-sized storage materials to have almost the same performance as small-sized materials for heat pump solar systems.
Kang Yang - One of the best experts on this subject based on the ideXlab platform.
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understanding wear interface evolution to Overcome Friction and restrain wear of tial 10 wt ag composite
Advanced Engineering Materials, 2018Co-Authors: Kang Yang, Xiyao LiuAbstract:The main objective of this paper is to study wear interface evolution for analyzing the of Friction and wear property of TiAl–10 wt%Ag composite. The results show that the Friction coefficient and wear rate of TiAl–10 wt%Ag rapidly reduce at 0–25 min and rhythmically fluctuate at 25–60 min. TiAl–10 wt%Ag at 60–240 min obtains low Friction and less wear. It is concluded that silver with the low shearing strength of about 125 MPa shows the eminent plastic deformation on wear interface. It effectively reduces Friction resistance and material loss, cause TiAl–10 wt%Ag to obtain low Friction coefficient, and less wear rate at 0–25 min. Increased silver content, reduces oxide content, and varies wear mechanisms cause the repeating variation of Friction resistance and material loss, which results in the rhythmical fluctuation of Friction coefficient and wear rate at 25–60 min. High silver contents exist on smooth wear interfaces, exhibit the eminent plastic deformation to lower Friction and reduce wear. TiAl–10 wt%Ag obtains the low Friction and less wear at 60–240 min.
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Understanding Wear Interface Evolution to Overcome Friction and Restrain Wear of TiAl–10 wt%Ag Composite
Advanced Engineering Materials, 2017Co-Authors: Kang Yang, Xiyao Liu, He QiangAbstract:The main objective of this paper is to study wear interface evolution for analyzing the of Friction and wear property of TiAl–10 wt%Ag composite. The results show that the Friction coefficient and wear rate of TiAl–10 wt%Ag rapidly reduce at 0–25 min and rhythmically fluctuate at 25–60 min. TiAl–10 wt%Ag at 60–240 min obtains low Friction and less wear. It is concluded that silver with the low shearing strength of about 125 MPa shows the eminent plastic deformation on wear interface. It effectively reduces Friction resistance and material loss, cause TiAl–10 wt%Ag to obtain low Friction coefficient, and less wear rate at 0–25 min. Increased silver content, reduces oxide content, and varies wear mechanisms cause the repeating variation of Friction resistance and material loss, which results in the rhythmical fluctuation of Friction coefficient and wear rate at 25–60 min. High silver contents exist on smooth wear interfaces, exhibit the eminent plastic deformation to lower Friction and reduce wear. TiAl–10 wt%Ag obtains the low Friction and less wear at 60–240 min.
