Steel H13 was put in non toxic salt bath with addition of CeO 2 for co diffusion of sulfur, nitrogen and carbon and followed by oxidation treatment. The effect of rare earths on the improvement of wear resistance a...Steel H13 was put in non toxic salt bath with addition of CeO 2 for co diffusion of sulfur, nitrogen and carbon and followed by oxidation treatment. The effect of rare earths on the improvement of wear resistance and high temperature oxidation resistance of steel H13 was studied using scanning electron microscope, energy dispersive spectrometry and X ray diffraction. The results show that compared to the surface treatment without rare earth addition, the treatment with addition of rare earths improves the wear resistance and high temperature resistance to oxidation of steel H13. Under the conditions of 30 N and 2 h, the wear weight loss was decreased by 40%, and the friction coefficient was reduced from 0 25 to 0 22; whereas for 150 N and 0 2 h, the wear weight loss was decreased by 24%, and the friction coefficient was reduced from 0 35 to 0 32. For the oxidation at 700 ℃ and 4 h, the rate of weight gain decreased to only about 1/30 of that without rare earths.展开更多
Because of the high affinity of the same element Ti,cemented carbide tools containing Ti seem to be non⁃optimal in machining titanium alloys.However,in practice,cemented carbide tools containing Ti are still widely us...Because of the high affinity of the same element Ti,cemented carbide tools containing Ti seem to be non⁃optimal in machining titanium alloys.However,in practice,cemented carbide tools containing Ti are still widely used in machining titanium alloys.Cutting experiments were conducted in order to systematically explain the contradictions between the practice and theory.The diffusion process between titanium alloys and the cemented carbide tools was analyzed by auger electron spectroscopy detecting the cutting regions.It was also analyzed by Ti/Co diffusion behavior simulated by molecular thermodynamics.The experimental results and the simulation results showed that the mutual diffusion of Ti/Co atoms was the major reason for the diffusion wear.The dissolution⁃diffusion wear was one of the main wear mechanisms for the cemented carbide tools containing Ti in the coatings.Moreover,four types of cemented carbide tools and two other types of cermet tools were used to machine the Ti⁃6Al⁃4V alloys at different cutting speeds to further verify the high affinity of cutting tools containing Ti in the substrate/coating.The verification experiments results showed that the cemented carbide tools containing Ti generally cannot be used for machining titanium alloys,but could show less affinity in the cutting regions with reasonable cutting conditions.展开更多
文摘Steel H13 was put in non toxic salt bath with addition of CeO 2 for co diffusion of sulfur, nitrogen and carbon and followed by oxidation treatment. The effect of rare earths on the improvement of wear resistance and high temperature oxidation resistance of steel H13 was studied using scanning electron microscope, energy dispersive spectrometry and X ray diffraction. The results show that compared to the surface treatment without rare earth addition, the treatment with addition of rare earths improves the wear resistance and high temperature resistance to oxidation of steel H13. Under the conditions of 30 N and 2 h, the wear weight loss was decreased by 40%, and the friction coefficient was reduced from 0 25 to 0 22; whereas for 150 N and 0 2 h, the wear weight loss was decreased by 24%, and the friction coefficient was reduced from 0 35 to 0 32. For the oxidation at 700 ℃ and 4 h, the rate of weight gain decreased to only about 1/30 of that without rare earths.
基金the National Science and Technology Major Project of China(Grant No.2019ZX04017001).
文摘Because of the high affinity of the same element Ti,cemented carbide tools containing Ti seem to be non⁃optimal in machining titanium alloys.However,in practice,cemented carbide tools containing Ti are still widely used in machining titanium alloys.Cutting experiments were conducted in order to systematically explain the contradictions between the practice and theory.The diffusion process between titanium alloys and the cemented carbide tools was analyzed by auger electron spectroscopy detecting the cutting regions.It was also analyzed by Ti/Co diffusion behavior simulated by molecular thermodynamics.The experimental results and the simulation results showed that the mutual diffusion of Ti/Co atoms was the major reason for the diffusion wear.The dissolution⁃diffusion wear was one of the main wear mechanisms for the cemented carbide tools containing Ti in the coatings.Moreover,four types of cemented carbide tools and two other types of cermet tools were used to machine the Ti⁃6Al⁃4V alloys at different cutting speeds to further verify the high affinity of cutting tools containing Ti in the substrate/coating.The verification experiments results showed that the cemented carbide tools containing Ti generally cannot be used for machining titanium alloys,but could show less affinity in the cutting regions with reasonable cutting conditions.
