The surface liquid segregation(SLS) phenomenon in semi-solid metal-high pressure die casting(SSM-HPDC) plates of 7075,2024,6082 and A201 was investigated by different techniques.Depth profiles were determined by first...The surface liquid segregation(SLS) phenomenon in semi-solid metal-high pressure die casting(SSM-HPDC) plates of 7075,2024,6082 and A201 was investigated by different techniques.Depth profiles were determined by firstly measuring the chemical composition of the surface of the plates using a Thermo Quantris optical emission spectrometer(OES).Material was then removed by a grinding process followed by measurement of the amount of material removed and chemical analysis.Chemical profiles of the main alloying elements were plotted for the cross-section of the plates in the as-cast and T6(after solution treatment) temper conditions.Vickers hardness profiles from the surface to the centre of the plates were determined.Metallographic samples of cross-sections of the castings were prepared and evaluated using a scanning electron microscope.The results show that surface liquid segregation in SSM-HPDC alloys causes significant differences in properties between the surface and the bulk of these castings in both the F and T6 temper conditions.展开更多
This present study applied gas tungsten arc welding in order to join AISI 304 and AISI 201 stainless steels.The objective was to find the optimum welding condition that gave a weld bead in accordance with DIN EN ISO 2...This present study applied gas tungsten arc welding in order to join AISI 304 and AISI 201 stainless steels.The objective was to find the optimum welding condition that gave a weld bead in accordance with DIN EN ISO 25817 quality level B, pitting corrosion potential of the weld metal of not less than that of the AISI304 base metal and a ratio of delta-ferrite in austenite matrix of the weld metal of not lower than 3%.Such a ratio is a criterion widely accepted to protect the weld metal from solidification cracking. At the welding current of 75 A and by using pure argon as a shielding gas 0 to 8 vol.% and applying a welding speed in the range of 2-3.5 mm·s^(-1) was found to give a complete weld bead with an increased depthper-width ratio(promote weldability). For welding speed in the range of 3 and 3.5 mm·s^(-1)(promote corrosion resistance). Increasing the welding speed in such a range decreased the amount of delta-ferrite in the austenite matrix, and increased the pitting corrosion potential of the weld metal to be 302 mV_(SCE).This value was still lower than the pitting corrosion potential of the AISI 304 base metal. Mixing nitrogen in argon shielding gas increased the nitrogen content in the weld. The optimum condition was found when using a welding speed of 3 mm· s^(-1) and mixing 1 vol.% of nitrogen in the argon shielding gas(promote weldability and corrosion resistance). Pitted areas after potentiodynamic test were observed in the austenite in which its Cr content was relatively low.展开更多
The Seppic Company developed a new adjuvant Montanide ISA 201 VG, the upgraded version of Montanide ISA 206 VG, which keep the advantage and added some chemical components on the basis of ISA 206 to improve the cellul...The Seppic Company developed a new adjuvant Montanide ISA 201 VG, the upgraded version of Montanide ISA 206 VG, which keep the advantage and added some chemical components on the basis of ISA 206 to improve the cellular responses. The aim of the study is to compare the efficacy of swine FMD (foot-and-mouth) vaccine emulsified with oil adjuvant of ISA 201 or ISA 206 respectively. The pigs were vaccinated with FMD vaccine emulsified with inactive FMD type O antigen and adjuvant ISA 201 or ISA 206 respectively, according to 2.0 ml (1/1 dose), 0.67 ml (1/3 dose), 0.22 ml (1/9 dose) to calculate their PD50. The sera were collected from the vaccination of the day 0, 3, 7, 14, 21, 28 and the ELISA FMD type O antibody were detected. Furthermore, the PD50 were calculated after the pigs were challenged with virulent FMDV type O on 28 days post vaccination. The ELISA antibody titers of 201vaccine were significantly higher than that of 206 (except the third time). The fifty percent of protection dose (PD50) of 201 vaccine (PD50 = 15.59) was higher than that of 206 vaccine (PD50 = 10.05). The above data showed that the efficacy of the FMD vaccine emulsified with ISA 201 was better than which with ISA 206.展开更多
文摘The surface liquid segregation(SLS) phenomenon in semi-solid metal-high pressure die casting(SSM-HPDC) plates of 7075,2024,6082 and A201 was investigated by different techniques.Depth profiles were determined by firstly measuring the chemical composition of the surface of the plates using a Thermo Quantris optical emission spectrometer(OES).Material was then removed by a grinding process followed by measurement of the amount of material removed and chemical analysis.Chemical profiles of the main alloying elements were plotted for the cross-section of the plates in the as-cast and T6(after solution treatment) temper conditions.Vickers hardness profiles from the surface to the centre of the plates were determined.Metallographic samples of cross-sections of the castings were prepared and evaluated using a scanning electron microscope.The results show that surface liquid segregation in SSM-HPDC alloys causes significant differences in properties between the surface and the bulk of these castings in both the F and T6 temper conditions.
基金the Thai Government scholarship given via Rajamangala University of Technology Krungthep (UTK), Bangkok, Thailand, for their financial support through this funded research project
文摘This present study applied gas tungsten arc welding in order to join AISI 304 and AISI 201 stainless steels.The objective was to find the optimum welding condition that gave a weld bead in accordance with DIN EN ISO 25817 quality level B, pitting corrosion potential of the weld metal of not less than that of the AISI304 base metal and a ratio of delta-ferrite in austenite matrix of the weld metal of not lower than 3%.Such a ratio is a criterion widely accepted to protect the weld metal from solidification cracking. At the welding current of 75 A and by using pure argon as a shielding gas 0 to 8 vol.% and applying a welding speed in the range of 2-3.5 mm·s^(-1) was found to give a complete weld bead with an increased depthper-width ratio(promote weldability). For welding speed in the range of 3 and 3.5 mm·s^(-1)(promote corrosion resistance). Increasing the welding speed in such a range decreased the amount of delta-ferrite in the austenite matrix, and increased the pitting corrosion potential of the weld metal to be 302 mV_(SCE).This value was still lower than the pitting corrosion potential of the AISI 304 base metal. Mixing nitrogen in argon shielding gas increased the nitrogen content in the weld. The optimum condition was found when using a welding speed of 3 mm· s^(-1) and mixing 1 vol.% of nitrogen in the argon shielding gas(promote weldability and corrosion resistance). Pitted areas after potentiodynamic test were observed in the austenite in which its Cr content was relatively low.
文摘The Seppic Company developed a new adjuvant Montanide ISA 201 VG, the upgraded version of Montanide ISA 206 VG, which keep the advantage and added some chemical components on the basis of ISA 206 to improve the cellular responses. The aim of the study is to compare the efficacy of swine FMD (foot-and-mouth) vaccine emulsified with oil adjuvant of ISA 201 or ISA 206 respectively. The pigs were vaccinated with FMD vaccine emulsified with inactive FMD type O antigen and adjuvant ISA 201 or ISA 206 respectively, according to 2.0 ml (1/1 dose), 0.67 ml (1/3 dose), 0.22 ml (1/9 dose) to calculate their PD50. The sera were collected from the vaccination of the day 0, 3, 7, 14, 21, 28 and the ELISA FMD type O antibody were detected. Furthermore, the PD50 were calculated after the pigs were challenged with virulent FMDV type O on 28 days post vaccination. The ELISA antibody titers of 201vaccine were significantly higher than that of 206 (except the third time). The fifty percent of protection dose (PD50) of 201 vaccine (PD50 = 15.59) was higher than that of 206 vaccine (PD50 = 10.05). The above data showed that the efficacy of the FMD vaccine emulsified with ISA 201 was better than which with ISA 206.
