The microstructural,mechanical and corrosion properties of different cold-rolled biomedical nickel-free highnitrogen stainless steels（NFHNSSs） were investigated to study the effect of cold deformation on its dry wea...The microstructural,mechanical and corrosion properties of different cold-rolled biomedical nickel-free highnitrogen stainless steels（NFHNSSs） were investigated to study the effect of cold deformation on its dry wear resistance as well as corrosion–wear behaviors in distilled water and Hank＇s solution. The results indicated that NFHNSS was characterized by stable austenite and possessed excellent work-hardening capacity; due to increasing cold deformation,the corrosion resistance just decreased very slightly and the dry wear rate decreased initially but subsequently increased,while the corrosion–wear resistance was improved monotonically in both distilled water and Hank＇s solution in spite of the presence of corrosive ions. The friction coefficients for different cold-rolled NFHNSSs were very close under the same lubricating condition,but they were the largest in distilled water compared to that in dry wear tests and Hank＇s solution.展开更多
Microstructure and mechanical properties of additively manufactured TC4 alloys were investigated,following boronizing treatment.The treatment process was carried out at temperatures ranging from 950 to 1050°C and...Microstructure and mechanical properties of additively manufactured TC4 alloys were investigated,following boronizing treatment.The treatment process was carried out at temperatures ranging from 950 to 1050°C and held for 8-15 h.The microstructural features of fabricated boride layers were examined by optical microscopy.The phase compositions of the boride layers were analyzed by X-ray diffraction.The hardness profile through the boride layers was also determined.The results showed that the boride layer of additively manufactured TC4 had a thickness of 51 pm and was composed of an outer TiB2 layer on the top of TiB layer;TiB whiskers wedged into the matrix,forming a strong bond between the boride layer and substrate.The diffusion activation energy was determined to be 80.9 kJ/mol.The matrix was found to transfer from needlelikeα'martensite phase toα+βbiphasic compounds.The newly formed boride layer can reach 1680 HV in hardness,thus imparting a strong protection to 3D-printed part.展开更多
基金supported by the National Natural Science Foundation of China(No.31370976)the National Basic Research Program of China(No.2012CB619101)
文摘The microstructural,mechanical and corrosion properties of different cold-rolled biomedical nickel-free highnitrogen stainless steels（NFHNSSs） were investigated to study the effect of cold deformation on its dry wear resistance as well as corrosion–wear behaviors in distilled water and Hank＇s solution. The results indicated that NFHNSS was characterized by stable austenite and possessed excellent work-hardening capacity; due to increasing cold deformation,the corrosion resistance just decreased very slightly and the dry wear rate decreased initially but subsequently increased,while the corrosion–wear resistance was improved monotonically in both distilled water and Hank＇s solution in spite of the presence of corrosive ions. The friction coefficients for different cold-rolled NFHNSSs were very close under the same lubricating condition,but they were the largest in distilled water compared to that in dry wear tests and Hank＇s solution.
文摘Microstructure and mechanical properties of additively manufactured TC4 alloys were investigated,following boronizing treatment.The treatment process was carried out at temperatures ranging from 950 to 1050°C and held for 8-15 h.The microstructural features of fabricated boride layers were examined by optical microscopy.The phase compositions of the boride layers were analyzed by X-ray diffraction.The hardness profile through the boride layers was also determined.The results showed that the boride layer of additively manufactured TC4 had a thickness of 51 pm and was composed of an outer TiB2 layer on the top of TiB layer;TiB whiskers wedged into the matrix,forming a strong bond between the boride layer and substrate.The diffusion activation energy was determined to be 80.9 kJ/mol.The matrix was found to transfer from needlelikeα'martensite phase toα+βbiphasic compounds.The newly formed boride layer can reach 1680 HV in hardness,thus imparting a strong protection to 3D-printed part.
