In this article,NiCr coatings with chromium content of 13%,27%and 41%were prepared by arc spraying.They were exposed in molten salts(NaCl-Na_(2)SO_(4))at 800℃for 200 hours.The effect of chromium content on the hot co...In this article,NiCr coatings with chromium content of 13%,27%and 41%were prepared by arc spraying.They were exposed in molten salts(NaCl-Na_(2)SO_(4))at 800℃for 200 hours.The effect of chromium content on the hot corrosion behavior of the coatings was in-vestigated.X-ray diffraction(XRD)and scanning electron microscope with energy dispersion spectrum(SEM-EDS)were used to analyze the phase compositions,morphologies and chemical compositions of the coatings.The results show that NiCr13 coating exhibited the worst hot corrosion resistance due to the low chromium content,which resulted in NiO being the major reaction product.It should be noted that the hot corrosion resistance of NiCr27 coating was better than that of NiCr41 coating.The basic fluxing of Cr_(2)O_(3) lowered its protection during the hot corrosion process and led to the formation of porous Cr_(2)O_(3) on the NiCr41 coating.The molten salts accelerated the oxidation reac-tion resulting in thicker and porous oxide scales formed on the surfaces of coatings.展开更多
As a metal alloy,NiCr films have a relatively high resistivity and low temperature coefficient of resistance (TCR) and are widely used in electronic components and sensors.However,the resistivity of pure NiCr is insuf...As a metal alloy,NiCr films have a relatively high resistivity and low temperature coefficient of resistance (TCR) and are widely used in electronic components and sensors.However,the resistivity of pure NiCr is insufficient for high-resistance and highly stable film resistors.In this study,a quaternary NiCrAlSi target (47:33:10:10,wt.%) was successfully used to prepare resistor films with resistivities ranging from 1000 to 10 000μΩcm and TCR within±100 ppm/K.An oxygen flow was introduced during the sputtering process.The films exhibit hightemperature stability at 450℃.The films were analyzed using Auger electron spectroscopy,x-ray diffraction,time-of-flight secondary-ion mass spectrometry,and x-ray photoelectron spectroscopy.The results show that the difference in the oxide proportion of the films caused the differences in resistivity.The near-zero TCR values were considered to be due to the competition between silicon and other metals.This study provides new insights into the electrical properties of NiCr-based films containing Si,which will drive the manufacturing of resistors with high resistivity and zero TCR.展开更多
用粉末冶金法制备不同 Ti C颗粒含量的 Ti C/ Ni Cr金属陶瓷复合材料 ,讨论了它们的显微组织特点 ,研究了该复合材料在水润滑条件下的摩擦磨损性能 .试验结果表明 :随着 Ti C颗粒含量增加 ,金属陶瓷的耐磨性能明显提高 ;在本试验条件下 ...用粉末冶金法制备不同 Ti C颗粒含量的 Ti C/ Ni Cr金属陶瓷复合材料 ,讨论了它们的显微组织特点 ,研究了该复合材料在水润滑条件下的摩擦磨损性能 .试验结果表明 :随着 Ti C颗粒含量增加 ,金属陶瓷的耐磨性能明显提高 ;在本试验条件下 ,当 Ti C颗粒体积分数为 6 7%左右时 ,Ti C/ Ni Cr金属陶瓷复合材料的耐磨性能最佳 ;其磨损失效机制主要是在磨损过程中 Ti C颗粒以显微脆断方式剥落产生磨损 。展开更多
基金supported by Corporate Talent Fund Program of Zhengzhou Research Institute of Mechanical Engineering Co.,Ltd.(No.201SJ2023013)the Faculty of Materials and Manufacturing,Beijing University of Technology.
文摘In this article,NiCr coatings with chromium content of 13%,27%and 41%were prepared by arc spraying.They were exposed in molten salts(NaCl-Na_(2)SO_(4))at 800℃for 200 hours.The effect of chromium content on the hot corrosion behavior of the coatings was in-vestigated.X-ray diffraction(XRD)and scanning electron microscope with energy dispersion spectrum(SEM-EDS)were used to analyze the phase compositions,morphologies and chemical compositions of the coatings.The results show that NiCr13 coating exhibited the worst hot corrosion resistance due to the low chromium content,which resulted in NiO being the major reaction product.It should be noted that the hot corrosion resistance of NiCr27 coating was better than that of NiCr41 coating.The basic fluxing of Cr_(2)O_(3) lowered its protection during the hot corrosion process and led to the formation of porous Cr_(2)O_(3) on the NiCr41 coating.The molten salts accelerated the oxidation reac-tion resulting in thicker and porous oxide scales formed on the surfaces of coatings.
基金support from the Innovation Foundation of the Shanghai Institute of Technical Physics,Chinese Academy of Sciences。
文摘As a metal alloy,NiCr films have a relatively high resistivity and low temperature coefficient of resistance (TCR) and are widely used in electronic components and sensors.However,the resistivity of pure NiCr is insufficient for high-resistance and highly stable film resistors.In this study,a quaternary NiCrAlSi target (47:33:10:10,wt.%) was successfully used to prepare resistor films with resistivities ranging from 1000 to 10 000μΩcm and TCR within±100 ppm/K.An oxygen flow was introduced during the sputtering process.The films exhibit hightemperature stability at 450℃.The films were analyzed using Auger electron spectroscopy,x-ray diffraction,time-of-flight secondary-ion mass spectrometry,and x-ray photoelectron spectroscopy.The results show that the difference in the oxide proportion of the films caused the differences in resistivity.The near-zero TCR values were considered to be due to the competition between silicon and other metals.This study provides new insights into the electrical properties of NiCr-based films containing Si,which will drive the manufacturing of resistors with high resistivity and zero TCR.
文摘用粉末冶金法制备不同 Ti C颗粒含量的 Ti C/ Ni Cr金属陶瓷复合材料 ,讨论了它们的显微组织特点 ,研究了该复合材料在水润滑条件下的摩擦磨损性能 .试验结果表明 :随着 Ti C颗粒含量增加 ,金属陶瓷的耐磨性能明显提高 ;在本试验条件下 ,当 Ti C颗粒体积分数为 6 7%左右时 ,Ti C/ Ni Cr金属陶瓷复合材料的耐磨性能最佳 ;其磨损失效机制主要是在磨损过程中 Ti C颗粒以显微脆断方式剥落产生磨损 。
