A simple impact-sliding wear test rig is designed for studying the wear behavior between solid materials on a repetitive normal impact accompanied with the tangential sliding. The test rig consists of a cantilever bea...A simple impact-sliding wear test rig is designed for studying the wear behavior between solid materials on a repetitive normal impact accompanied with the tangential sliding. The test rig consists of a cantilever beam forced by the dynamoelectric vibration exciter and a rotational shaft driven by a spindle. It has a widely adjustable range of testing parameters, including the impact frequency, the impact load and the sliding velocity. The avail- able maximum impact frequency, impact load and sliding velocity are 100 Hz, 200 N and 4.52 m/s, respectively. To evaluate the capability of the test rig, tests are carried out and the impact load is measured. Results show that the test rig has the good repeatability under the same test conditions and the repeatable error is less than 7%. Furthermore, non-destructive examination results by the mass loss method, two-dimensional profilometry and the scanning electron microscopy （SEM） show that the test rig can meet the demands for the impact-sliding wear.展开更多
Self-lubricating A1203-15wt% ZrO2 composites with sulfides, such as molybdenum disulfide （MoS2） and tungsten disulfide （WSz） serving as solid lubricants, were fabricated by using the pulse electric current sinteri...Self-lubricating A1203-15wt% ZrO2 composites with sulfides, such as molybdenum disulfide （MoS2） and tungsten disulfide （WSz） serving as solid lubricants, were fabricated by using the pulse electric current sintering （PECS） technique. The coefficient of friction （COF） of the A1203-15wt% ZrO2 composite without/with sulfides was in the range of 0.37-0.48 and 0.27-0.49, respectively. As the amoant of sul- fides increased, the COF and the wear rate decreased. The reduction in COF and wear rate of the sulfide-containing composite is caused by a reduction in shear stresses between the specimen and the tribological medium due to the formation of a lubricating film resulting from the lamellar structure of sulfides located on the worn surface.展开更多
Aluminum alloy 2024 has been implanted with nitrogen ions at various doses by plasma based ion implantation. The introduction of energetic ions causes structural change within the near surface region of the solid. The...Aluminum alloy 2024 has been implanted with nitrogen ions at various doses by plasma based ion implantation. The introduction of energetic ions causes structural change within the near surface region of the solid. The samples have been characterized by X-ray Photoelectron Spectroscopy at various depths. The chemical states of Al and N were identified by deconvolution of the recorded XPS spectra. After plasma based ion implanted nitrogen into aluminum, not only the AlN precipitates but also super saturated solution of nitrogen forms. The presence of aluminum in different chemical states is corresponding to Al, AlN and Al2O3. The majority of nitrogen is in the form of the supersaturated solution. With the increase of nitrogen dose, the amount of AlN precipitates increases.展开更多
Based on the micro-morphology theory, the authors set up a set of feature descriptors of debris, use it to abstract the characteristic information of wearing particles, and identify them by the auto clustering, Artifi...Based on the micro-morphology theory, the authors set up a set of feature descriptors of debris, use it to abstract the characteristic information of wearing particles, and identify them by the auto clustering, Artificial Neural Network (ANN) and other artificial intelligence (AI) means. The technique has found its application in the wearing fault diagnosis of aero-engines.展开更多
基金Supported by the National Basic Research Program of China("973"Program)(2007CB607602)~~
文摘A simple impact-sliding wear test rig is designed for studying the wear behavior between solid materials on a repetitive normal impact accompanied with the tangential sliding. The test rig consists of a cantilever beam forced by the dynamoelectric vibration exciter and a rotational shaft driven by a spindle. It has a widely adjustable range of testing parameters, including the impact frequency, the impact load and the sliding velocity. The avail- able maximum impact frequency, impact load and sliding velocity are 100 Hz, 200 N and 4.52 m/s, respectively. To evaluate the capability of the test rig, tests are carried out and the impact load is measured. Results show that the test rig has the good repeatability under the same test conditions and the repeatable error is less than 7%. Furthermore, non-destructive examination results by the mass loss method, two-dimensional profilometry and the scanning electron microscopy （SEM） show that the test rig can meet the demands for the impact-sliding wear.
基金financially supported by the Korea Foundation for International Cooperation of Science and Technology(KICOS 2008-0143)the Global Research Laboratory(GRL)Program of the National Research Foundation of Korea(NRF)funded by the Ministry of Education,Science,and Technology(MEST)of Korea(No.2010-00339)
文摘Self-lubricating A1203-15wt% ZrO2 composites with sulfides, such as molybdenum disulfide （MoS2） and tungsten disulfide （WSz） serving as solid lubricants, were fabricated by using the pulse electric current sintering （PECS） technique. The coefficient of friction （COF） of the A1203-15wt% ZrO2 composite without/with sulfides was in the range of 0.37-0.48 and 0.27-0.49, respectively. As the amoant of sul- fides increased, the COF and the wear rate decreased. The reduction in COF and wear rate of the sulfide-containing composite is caused by a reduction in shear stresses between the specimen and the tribological medium due to the formation of a lubricating film resulting from the lamellar structure of sulfides located on the worn surface.
文摘Aluminum alloy 2024 has been implanted with nitrogen ions at various doses by plasma based ion implantation. The introduction of energetic ions causes structural change within the near surface region of the solid. The samples have been characterized by X-ray Photoelectron Spectroscopy at various depths. The chemical states of Al and N were identified by deconvolution of the recorded XPS spectra. After plasma based ion implanted nitrogen into aluminum, not only the AlN precipitates but also super saturated solution of nitrogen forms. The presence of aluminum in different chemical states is corresponding to Al, AlN and Al2O3. The majority of nitrogen is in the form of the supersaturated solution. With the increase of nitrogen dose, the amount of AlN precipitates increases.
文摘Based on the micro-morphology theory, the authors set up a set of feature descriptors of debris, use it to abstract the characteristic information of wearing particles, and identify them by the auto clustering, Artificial Neural Network (ANN) and other artificial intelligence (AI) means. The technique has found its application in the wearing fault diagnosis of aero-engines.
