The factors of heat treatments were discussed, which affect the formability of two low carbon, low alloy steels. Experiment concerns mechanical properties, R-values, orientation intensity, texture internal friction an...The factors of heat treatments were discussed, which affect the formability of two low carbon, low alloy steels. Experiment concerns mechanical properties, R-values, orientation intensity, texture internal friction and their relationship with annealing and ageing.展开更多
The composition of a bearing steel was designed for limited hardenability by use of Grossmann's method. A medium frequency induction Process was applied to heat bearings to ensure penetrant heating and suitable so...The composition of a bearing steel was designed for limited hardenability by use of Grossmann's method. A medium frequency induction Process was applied to heat bearings to ensure penetrant heating and suitable solving of carbon and other elements in the matrix. The hardened depth measured from the end quenching test samples and actual bearings matches well with the designed one.展开更多
Oscillatory changes in resistivity of palladium coil based sensors were studied in the presence of carbon monoxide under constant operating current.Oscillations in resistance were observed at operating temperature ran...Oscillatory changes in resistivity of palladium coil based sensors were studied in the presence of carbon monoxide under constant operating current.Oscillations in resistance were observed at operating temperature ranging from 100℃to 130℃.Both the period and the amplitude of the waveform increased with increasing CO concentration.It is believed that oscillations occurred between two branches of a Langmuir-Hinshelwood reaction mechanism.展开更多
Some practical research topics on tunable fiber gratings in author's group are presented, including tuning speed, tuning range, tuning characteristics of gratings in HB fiber, and the tunability of the line-width....Some practical research topics on tunable fiber gratings in author's group are presented, including tuning speed, tuning range, tuning characteristics of gratings in HB fiber, and the tunability of the line-width. The applications of fiber gratings in communication and sensing are also discussed.展开更多
A novel two-step cooling experiment was established to simulate the slow cooling process of continuous annealing production line for transformation-induced plasticity （TRIP） steel. The microstructures and mechanical...A novel two-step cooling experiment was established to simulate the slow cooling process of continuous annealing production line for transformation-induced plasticity （TRIP） steel. The microstructures and mechanical properties of TRIP steel soaked at 700℃ for different time were investigated by tensile test, scanning electron microscopy, X-ray diffraction, and thermodynamic and kinetic calculation. It is shown that the steel soaked for 15 s exhibits the optimal product of strength and elongation （PSE 〉 30,000 MPa%） due to the transformation of austenite to proeutectoid ferrite, which delays the bainite transformation and improves the stability of retained austenite. In addition, the mechanical properties of TRIP steel soaked over 30 s are much lower, resulting from the precipitation of cementite, which decreases the stability of retained austenite and weakens the TRIP effect.展开更多
In this study, the surface passive films, dissolution behavior and biocompatibility of Ti-Ag alloys （with 5%, 10% and 20% Ag） were evaluated by X-ray diffraction （XRD） tests, electrochemical corrosion tests, X-ray...In this study, the surface passive films, dissolution behavior and biocompatibility of Ti-Ag alloys （with 5%, 10% and 20% Ag） were evaluated by X-ray diffraction （XRD） tests, electrochemical corrosion tests, X-ray photoelectron spectroscopy （XPS） tests, dissolution tests and in-vitro cytotoxicity tests. The surface films on the Ti-20Ag alloy are rich in Ti and much deficient in Ag with respect to alloy composition, as identified by XPS. Compared to CP Ti, Ti-SAg and Ti-20Ag alloys show larger impedances and lower capacitances, which can be associated with an increase of the passive layer thickness. Moreover, all Ti-Ag alloys exhibit negligible or low metal release in the test solutions. The in-vitro cytotoxicity results show Ti-Ag alloys seem to be as cytocompatible as CP Ti. From the viewpoint of surface passive film and cytotoxicity, Ti-SAg and Ti-20Ag are considered to be more suitable for dental applications.展开更多
基金Acknowledgments Foundation item： National Science Foundation of China （No. 50808068） The Ph.D. Programs Foundation of Ministry of Education of China （No. 200802941001）.
基金This boas was financially seaported by SAIC FUND 3166A.
文摘The factors of heat treatments were discussed, which affect the formability of two low carbon, low alloy steels. Experiment concerns mechanical properties, R-values, orientation intensity, texture internal friction and their relationship with annealing and ageing.
文摘The composition of a bearing steel was designed for limited hardenability by use of Grossmann's method. A medium frequency induction Process was applied to heat bearings to ensure penetrant heating and suitable solving of carbon and other elements in the matrix. The hardened depth measured from the end quenching test samples and actual bearings matches well with the designed one.
基金Acknowledgments Foundation item： National Science Foundation of China （50808068） The Ph.D. Programs Foundation of Ministry of Education of China （200802941001）.
文摘Oscillatory changes in resistivity of palladium coil based sensors were studied in the presence of carbon monoxide under constant operating current.Oscillations in resistance were observed at operating temperature ranging from 100℃to 130℃.Both the period and the amplitude of the waveform increased with increasing CO concentration.It is believed that oscillations occurred between two branches of a Langmuir-Hinshelwood reaction mechanism.
文摘Some practical research topics on tunable fiber gratings in author's group are presented, including tuning speed, tuning range, tuning characteristics of gratings in HB fiber, and the tunability of the line-width. The applications of fiber gratings in communication and sensing are also discussed.
基金This work was supported by National Key R＆D Program of China （Grant No. 2017YFB0304402） and the Shanghai Municipal Natural Science Foundation （Grant No. 17ZR1410400）.
文摘A novel two-step cooling experiment was established to simulate the slow cooling process of continuous annealing production line for transformation-induced plasticity （TRIP） steel. The microstructures and mechanical properties of TRIP steel soaked at 700℃ for different time were investigated by tensile test, scanning electron microscopy, X-ray diffraction, and thermodynamic and kinetic calculation. It is shown that the steel soaked for 15 s exhibits the optimal product of strength and elongation （PSE 〉 30,000 MPa%） due to the transformation of austenite to proeutectoid ferrite, which delays the bainite transformation and improves the stability of retained austenite. In addition, the mechanical properties of TRIP steel soaked over 30 s are much lower, resulting from the precipitation of cementite, which decreases the stability of retained austenite and weakens the TRIP effect.
基金supported by the National Basic Research Program of China ("973 Program", Nos.2012CB619102 and 2012CB619100)the National High Technology Research and Development Program of China ("863 Program", Nos. 2011AA030101 and2011AA030103)+3 种基金the National Natural Science Foundation of China (Nos. 31170909 and 51041004)the Research Fund for the Doctoral Program of Higher Education (No. 20100001110011)the Fundamental Research Funds for the Central Universities (Nos. HEUCFZ1017and HEUCFR1020)the Natural Science Foundation of Heilongjiang Province, China (No. ZD201012)
文摘In this study, the surface passive films, dissolution behavior and biocompatibility of Ti-Ag alloys （with 5%, 10% and 20% Ag） were evaluated by X-ray diffraction （XRD） tests, electrochemical corrosion tests, X-ray photoelectron spectroscopy （XPS） tests, dissolution tests and in-vitro cytotoxicity tests. The surface films on the Ti-20Ag alloy are rich in Ti and much deficient in Ag with respect to alloy composition, as identified by XPS. Compared to CP Ti, Ti-SAg and Ti-20Ag alloys show larger impedances and lower capacitances, which can be associated with an increase of the passive layer thickness. Moreover, all Ti-Ag alloys exhibit negligible or low metal release in the test solutions. The in-vitro cytotoxicity results show Ti-Ag alloys seem to be as cytocompatible as CP Ti. From the viewpoint of surface passive film and cytotoxicity, Ti-SAg and Ti-20Ag are considered to be more suitable for dental applications.
