In this paper we compare the wear behaviour of a vacuum-heat-treated ESR AISI M2 high-speed steel and the same steel that was vacuum heat treated in conjunction with a deep-cryogenic treatment at -196 °C. Four di...In this paper we compare the wear behaviour of a vacuum-heat-treated ESR AISI M2 high-speed steel and the same steel that was vacuum heat treated in conjunction with a deep-cryogenic treatment at -196 °C. Four different tempering temperatures for the specimens austenized at the same austenitizing temperature were carefully selected to obtain various in-advance-determined combinations of the microstructures, the fracture toughness, KIc and the Rockwell-C hardness. Each of the eight specimens was therefore characterised by these microstructures and resulting material properties. The wear study was performed using a reciprocating sliding device under well-controlled contact conditions. Relatively high loads were used to provide enough wear for a comparison of the selected samples. A much harder and dissimilar model counter-material, i.e. silicon nitride ceramic, was used in order to avoid excessive wear of the counter samples and adhesion, which could occur in contacts with similar materials (metals/steels) under such high loads and in non-lubricated conditions. The wear behaviours were then compared and discussed in terms of these microstructures and the related properties. The differences in the wear resistance obtained in our investigation were as high as an order of magnitude. However, the beneficial effects are not a direct result of the type of the treatment, but relate to a proper combination of the resulting fracture toughness and the hardness. The more uniform and moderate values, which, however, tend to be obtained with a deep-cryogenic treatment, are beneficial to the high wear resistance of the selected high-speed steel.展开更多
Stainless steel (SS) 410 is widely used in many components of nuclear reactors due to its good corrosion resistance and high strength. However, wear is a major issue of these components due to its continuous sliding. ...Stainless steel (SS) 410 is widely used in many components of nuclear reactors due to its good corrosion resistance and high strength. However, wear is a major issue of these components due to its continuous sliding. SS 420 and Colmonoy 5 particles were deposited over SS 410 substrate by laser cladding process. Then, X-ray diffraction was used to find the phases present after cladding process. Further, coating morphologies were analysed by scanning electron microscopy (SEM) twinned with energy-dispersive spectroscopy. The obtained morphology indicates the hard laves phase present in the Colmonoy 5 cladding surface and needle-like structure in SS 420 cladding surface. Then, Vickers microhardness test was carried out in order to study the hardness and load-carrying capacity of the cladding specimen. Among those, Colmonoy 5 cladding specimen provide higher hardness due to the presence of laves phase formation. Then, the dry sliding wear study was conducted to calculate the mass loss after 2500 m of sliding. The combined effect of hardness and laves phase formation were reflected in dry sliding wear study analysis of the specimens. Then, to study the wear mechanism and roughness, worn surface morphologies were captured using SEM and white light interferometer, respectively.展开更多
Tribological behaviour of aluminium alloy (Al-Si10Mg) reinforced with alumina (9%) and graphite (3%) fabricated by stir casting process was investigated. The wear and frictional properties of the hybrid metal matrix c...Tribological behaviour of aluminium alloy (Al-Si10Mg) reinforced with alumina (9%) and graphite (3%) fabricated by stir casting process was investigated. The wear and frictional properties of the hybrid metal matrix composites was studied by performing dry sliding wear test using a pin-on-disc wear tester. Experiments were conducted based on the plan of experiments generated through Taguchi’s technique. A L27 Orthogonal array was selected for analysis of the data. Investigation to find the influence of applied load, sliding speed and sliding distance on wear rate, as well as the coefficient of friction during wearing process was carried out using ANOVA and regression equations for each response were developed. Objective of the model was chosen as ‘smaller the better’ characteristics to analyse the dry sliding wear resistance. Results show that sliding distance has the highest influence followed by load and sliding speed. Finally, confirmation tests were carried out to verify the experimental results and Scanning Electron Microscopic studies were done on the wear surfaces.展开更多
Experimental study of the effect of wear parameters on the wear behaviour of A356 alloy reinforced with cow horn particles(CHp) produced by spark plasma sintering was investigated. Experiments were conducted based on ...Experimental study of the effect of wear parameters on the wear behaviour of A356 alloy reinforced with cow horn particles(CHp) produced by spark plasma sintering was investigated. Experiments were conducted based on the plan of experiments generated through Taguchi's(L9) technique. Tribometer was used for the wear test and Scanning electron microscope was used to analyse the worn scar of the samples. The results shows that, A356 alloy reinforced with CHp exhibited better dry sliding wear resistance than the unreinforced alloy. Wear rate decreased as the amount of CHp reinforcement increased in the matrix. It was found that, the optimum level of the factors with minimized the wear loss were obtained at: wt%CHp(20%), applied load(10 N), sliding velocity(3 m/s) and sliding distance(2000 m). It can be seen that the wear track of the sample are(D ? 0.81 and L = 42.85 mm) and(D ? 0.54 and L= 27.03 mm) for A356 alloy and composites at optimum condition respectively. The results showed that the addition of cow horn particles as reinforcing materials in A356 alloy composites increased the wear resistance of the composites greatly.展开更多
文摘In this paper we compare the wear behaviour of a vacuum-heat-treated ESR AISI M2 high-speed steel and the same steel that was vacuum heat treated in conjunction with a deep-cryogenic treatment at -196 °C. Four different tempering temperatures for the specimens austenized at the same austenitizing temperature were carefully selected to obtain various in-advance-determined combinations of the microstructures, the fracture toughness, KIc and the Rockwell-C hardness. Each of the eight specimens was therefore characterised by these microstructures and resulting material properties. The wear study was performed using a reciprocating sliding device under well-controlled contact conditions. Relatively high loads were used to provide enough wear for a comparison of the selected samples. A much harder and dissimilar model counter-material, i.e. silicon nitride ceramic, was used in order to avoid excessive wear of the counter samples and adhesion, which could occur in contacts with similar materials (metals/steels) under such high loads and in non-lubricated conditions. The wear behaviours were then compared and discussed in terms of these microstructures and the related properties. The differences in the wear resistance obtained in our investigation were as high as an order of magnitude. However, the beneficial effects are not a direct result of the type of the treatment, but relate to a proper combination of the resulting fracture toughness and the hardness. The more uniform and moderate values, which, however, tend to be obtained with a deep-cryogenic treatment, are beneficial to the high wear resistance of the selected high-speed steel.
基金Ministry of Science and Technology(MOST),Taiwan,China,for providing financial support to carry out this research work.
文摘Stainless steel (SS) 410 is widely used in many components of nuclear reactors due to its good corrosion resistance and high strength. However, wear is a major issue of these components due to its continuous sliding. SS 420 and Colmonoy 5 particles were deposited over SS 410 substrate by laser cladding process. Then, X-ray diffraction was used to find the phases present after cladding process. Further, coating morphologies were analysed by scanning electron microscopy (SEM) twinned with energy-dispersive spectroscopy. The obtained morphology indicates the hard laves phase present in the Colmonoy 5 cladding surface and needle-like structure in SS 420 cladding surface. Then, Vickers microhardness test was carried out in order to study the hardness and load-carrying capacity of the cladding specimen. Among those, Colmonoy 5 cladding specimen provide higher hardness due to the presence of laves phase formation. Then, the dry sliding wear study was conducted to calculate the mass loss after 2500 m of sliding. The combined effect of hardness and laves phase formation were reflected in dry sliding wear study analysis of the specimens. Then, to study the wear mechanism and roughness, worn surface morphologies were captured using SEM and white light interferometer, respectively.
文摘Tribological behaviour of aluminium alloy (Al-Si10Mg) reinforced with alumina (9%) and graphite (3%) fabricated by stir casting process was investigated. The wear and frictional properties of the hybrid metal matrix composites was studied by performing dry sliding wear test using a pin-on-disc wear tester. Experiments were conducted based on the plan of experiments generated through Taguchi’s technique. A L27 Orthogonal array was selected for analysis of the data. Investigation to find the influence of applied load, sliding speed and sliding distance on wear rate, as well as the coefficient of friction during wearing process was carried out using ANOVA and regression equations for each response were developed. Objective of the model was chosen as ‘smaller the better’ characteristics to analyse the dry sliding wear resistance. Results show that sliding distance has the highest influence followed by load and sliding speed. Finally, confirmation tests were carried out to verify the experimental results and Scanning Electron Microscopic studies were done on the wear surfaces.
文摘Experimental study of the effect of wear parameters on the wear behaviour of A356 alloy reinforced with cow horn particles(CHp) produced by spark plasma sintering was investigated. Experiments were conducted based on the plan of experiments generated through Taguchi's(L9) technique. Tribometer was used for the wear test and Scanning electron microscope was used to analyse the worn scar of the samples. The results shows that, A356 alloy reinforced with CHp exhibited better dry sliding wear resistance than the unreinforced alloy. Wear rate decreased as the amount of CHp reinforcement increased in the matrix. It was found that, the optimum level of the factors with minimized the wear loss were obtained at: wt%CHp(20%), applied load(10 N), sliding velocity(3 m/s) and sliding distance(2000 m). It can be seen that the wear track of the sample are(D ? 0.81 and L = 42.85 mm) and(D ? 0.54 and L= 27.03 mm) for A356 alloy and composites at optimum condition respectively. The results showed that the addition of cow horn particles as reinforcing materials in A356 alloy composites increased the wear resistance of the composites greatly.
