Thermal spraying has emerged as a suitable and effective surface engineering technology and is widely used to apply wear, erosion and corrosion protective coatings for various kinds of industrial applications. Cr3C2-b...Thermal spraying has emerged as a suitable and effective surface engineering technology and is widely used to apply wear, erosion and corrosion protective coatings for various kinds of industrial applications. Cr3C2-based coatings have been applied to a wide range of industrial components. Cr3C2-NiCr coatings offer greater corrosion and oxidation resistance, also having a high melting point and maintaining high hardness, strength and wear resistance up to a maximum operating temperature of 900 °C. The corrosion resistance is provided by NiCr matrix while the wear resistance is mainly due to the carbide ceramic phase. This paper reviews the performance, developments and applications of Cr3C2-NiCr thermal spray coatings for corrosion/erosion-corrosion under different types of environments and outlines the characterization of Cr3C2-NiCr coatings with respect to their microstructure and mechanical properties, together with some brief characterisation work by the author for HVOF sprayed 75Cr3C2-25NiCr coating on T91 boiler steel.展开更多
In machining processes,researchers are actively engaged in exploring minimum quantity lubrication(MQL)as a possible alternative to traditional flood cooling owing to economic and ecological concerns.The search for eco...In machining processes,researchers are actively engaged in exploring minimum quantity lubrication(MQL)as a possible alternative to traditional flood cooling owing to economic and ecological concerns.The search for ecologically safe lubricants has attracted the attention of scientists looking to use vegetable oil as a lubricant.The nanofluid MQL technique with biodegradable oils as the base is a relatively new method with the potential to replace mineral oils.In the present study,the grinding of Inconel-718 alloy was investigated using nanofluid MQL(NFMQL)with biodegradable oils as the base.Nanofluids are composed by dispersing 0.5%(mass fraction)and 1%(mass fraction)of CuO nanoparticles in vegetable oil.The surface morphology,G-ratio,forces,and grinding energy were examined under pure MQL,NFMQL,and dry and flood lubrication conditions.The experimental results indicated that the nanofluid MQL significantly improved the machining performance.Owing to the polishing and rolling effect of nanoparticles on the tool work interface,a surface finish under a 0.5%(mass fraction)nanofluid was found to be better than pure MQL-dry and flood lubrication conditions.The NFMQL technique with 1%(mass fraction)CuO nanoparticles with palm oil as the base helped in achieving a better evacuation of chips from the grinding zone,leading to a better surface finish with a high material removal rate along with less energy consumption compared to flood and dry grinding.展开更多
文摘Thermal spraying has emerged as a suitable and effective surface engineering technology and is widely used to apply wear, erosion and corrosion protective coatings for various kinds of industrial applications. Cr3C2-based coatings have been applied to a wide range of industrial components. Cr3C2-NiCr coatings offer greater corrosion and oxidation resistance, also having a high melting point and maintaining high hardness, strength and wear resistance up to a maximum operating temperature of 900 °C. The corrosion resistance is provided by NiCr matrix while the wear resistance is mainly due to the carbide ceramic phase. This paper reviews the performance, developments and applications of Cr3C2-NiCr thermal spray coatings for corrosion/erosion-corrosion under different types of environments and outlines the characterization of Cr3C2-NiCr coatings with respect to their microstructure and mechanical properties, together with some brief characterisation work by the author for HVOF sprayed 75Cr3C2-25NiCr coating on T91 boiler steel.
文摘In machining processes,researchers are actively engaged in exploring minimum quantity lubrication(MQL)as a possible alternative to traditional flood cooling owing to economic and ecological concerns.The search for ecologically safe lubricants has attracted the attention of scientists looking to use vegetable oil as a lubricant.The nanofluid MQL technique with biodegradable oils as the base is a relatively new method with the potential to replace mineral oils.In the present study,the grinding of Inconel-718 alloy was investigated using nanofluid MQL(NFMQL)with biodegradable oils as the base.Nanofluids are composed by dispersing 0.5%(mass fraction)and 1%(mass fraction)of CuO nanoparticles in vegetable oil.The surface morphology,G-ratio,forces,and grinding energy were examined under pure MQL,NFMQL,and dry and flood lubrication conditions.The experimental results indicated that the nanofluid MQL significantly improved the machining performance.Owing to the polishing and rolling effect of nanoparticles on the tool work interface,a surface finish under a 0.5%(mass fraction)nanofluid was found to be better than pure MQL-dry and flood lubrication conditions.The NFMQL technique with 1%(mass fraction)CuO nanoparticles with palm oil as the base helped in achieving a better evacuation of chips from the grinding zone,leading to a better surface finish with a high material removal rate along with less energy consumption compared to flood and dry grinding.
