By using a self-developed IF power and a ASTM contact material experimental system of small-capacity and variable frequency,the value of arcing characteristics and the welding force of the silver-based contact materia...By using a self-developed IF power and a ASTM contact material experimental system of small-capacity and variable frequency,the value of arcing characteristics and the welding force of the silver-based contact material are acquired under low voltage,resistive load and small current at 400 Hz and 50 Hz. By means of an electricity-ray analytical balance,SEM and EDAX,the weighing values of the contact materials and the changes of AgCdO,AgNi,AgC and AgW contact material surface profile and micro-area constituent are obtained and analyzed. The arc erosion causes of silver-based alloy contact materials at 400 Hz and 50 Hz are also discussed.展开更多
The Ta_(2)AlC material is designed to enhance the performance of Ag-based electrical contact materials as areinforcement phase.With a work function of 6.7192 eV,Ta_(2)AlC demonstrated significantly higher values thanr...The Ta_(2)AlC material is designed to enhance the performance of Ag-based electrical contact materials as areinforcement phase.With a work function of 6.7192 eV,Ta_(2)AlC demonstrated significantly higher values thanreinforcement phase materials such as SnO_(2),ZrO_(2),and the commonly used MAX phase materials.Consequently,the arcerosion performance of an Ag–Ta_(2)AlC composite was investigated under air conditions.Gas breakdown mainly occurreddue to electron avalanches,with the observation of a streamer breakdown mechanism in a strongly nonuniform field.Thearc exhibited concentrated erosion on the surface of the Ag–20 vol%Ta_(2)AlC material,resulting in a higher arc energy.Asthe volume fraction of the Ta_(2)AlC material increased to 30%and 40%,the eroded area became more dispersed.Inparticular,Ag–30 vol%Ta_(2)AlC displayed the lowest arc energy(3.395 kJ)and shortest arcing time(33.26 ms).Among thefour tested components,the Ag–30 vol%Ta_(2)AlC composite demonstrated superior arc erosion resistance.Oxides of Ag_(2)O,AgO,Ta_(2)O_(5),and Al_(2)O_(3)were formed through the interaction of ionized Ag and Ta_(2)AlC particles.By combining theelectromagnetic force and plasma flow force,sputtered particles and bulges were generated on the eroded surface.Theseresearch findings contribute to broadening the applications of Ag–MAX materials in the realm of electrical contacts.展开更多
A super-fine compound powder, Ag/SnO_2+La_2O_3+ Bi_2O_3, has been obtainedusing the chemical coprecipitation method. And a new contact material, Ag/SnO_2+La_2O_3+Bi_2O_3, wasproduced by the powder metallurgy method. I...A super-fine compound powder, Ag/SnO_2+La_2O_3+ Bi_2O_3, has been obtainedusing the chemical coprecipitation method. And a new contact material, Ag/SnO_2+La_2O_3+Bi_2O_3, wasproduced by the powder metallurgy method. Its properties are as follows: the density is 9.75-9.93g/cm^3, the resistivity is 2.31-2.55 μΩ ·cm, the hardness is 880-985 MPa. Its mi-crostructureshows that the fine oxides have a uniform distribution in the silver matrix. The results ofmake-break capacity and temperature rise testing show that the new material has better ability ofanti-arc erosion and lower temperature rise than that of commonly used Ag/CdO.展开更多
A new silver rare earth oxide contact material, Ag/La2O3(12), was produced by powder metallurgy method. Its performances are as follows: the density is 9.71 similar to 9.96 g.cm(-3); the hardness (HB) is 760 similar t...A new silver rare earth oxide contact material, Ag/La2O3(12), was produced by powder metallurgy method. Its performances are as follows: the density is 9.71 similar to 9.96 g.cm(-3); the hardness (HB) is 760 similar to 970 MPa and the resistivity is 2.25 similar to 2.38 mu Omega . cm. The microstructure of Ag/La2O3(12) mas analyzed by SEM and EDS. Rare earth oxide La2O3 shows two shapes, which are uniformly distributed in the form of sphere and abnormality in Ag matrix. La2O3 shows fine spherical shape in the melted area of Ag after laser acting which is used to simulate electric are. The results are contributed to the less splash erosion of Ag. Compared with the main physical and mechanical properties of Ag/SnO2(12) and Ag/CdO(12), the properties of three contact materials are similar, and hence Ag/La2O3(12) may become a potential contact material to be used as the substitute of Ag/CdO(12).展开更多
基金supported by the Hunan Natural Science Foundation in China (No.05JJ40068)
文摘By using a self-developed IF power and a ASTM contact material experimental system of small-capacity and variable frequency,the value of arcing characteristics and the welding force of the silver-based contact material are acquired under low voltage,resistive load and small current at 400 Hz and 50 Hz. By means of an electricity-ray analytical balance,SEM and EDAX,the weighing values of the contact materials and the changes of AgCdO,AgNi,AgC and AgW contact material surface profile and micro-area constituent are obtained and analyzed. The arc erosion causes of silver-based alloy contact materials at 400 Hz and 50 Hz are also discussed.
基金supported by the Nature Science Foundation of Anhui Province,China(Nos.2208085ME104,1908085QE218)the University Natural Science Research Project of Anhui Province(Nos.KJ2021ZD0141,2022AH051589)+2 种基金the Cultivation Programme for the Outstanding Young Teachers of Anhui Province(No.YQYB2023054)the Application Project of Bengbu Univerisity(No.2024YYX29QD)the Guiding Science and Technology Plan Project in Huainan City(No.2023017).
文摘The Ta_(2)AlC material is designed to enhance the performance of Ag-based electrical contact materials as areinforcement phase.With a work function of 6.7192 eV,Ta_(2)AlC demonstrated significantly higher values thanreinforcement phase materials such as SnO_(2),ZrO_(2),and the commonly used MAX phase materials.Consequently,the arcerosion performance of an Ag–Ta_(2)AlC composite was investigated under air conditions.Gas breakdown mainly occurreddue to electron avalanches,with the observation of a streamer breakdown mechanism in a strongly nonuniform field.Thearc exhibited concentrated erosion on the surface of the Ag–20 vol%Ta_(2)AlC material,resulting in a higher arc energy.Asthe volume fraction of the Ta_(2)AlC material increased to 30%and 40%,the eroded area became more dispersed.Inparticular,Ag–30 vol%Ta_(2)AlC displayed the lowest arc energy(3.395 kJ)and shortest arcing time(33.26 ms).Among thefour tested components,the Ag–30 vol%Ta_(2)AlC composite demonstrated superior arc erosion resistance.Oxides of Ag_(2)O,AgO,Ta_(2)O_(5),and Al_(2)O_(3)were formed through the interaction of ionized Ag and Ta_(2)AlC particles.By combining theelectromagnetic force and plasma flow force,sputtered particles and bulges were generated on the eroded surface.Theseresearch findings contribute to broadening the applications of Ag–MAX materials in the realm of electrical contacts.
基金This project is financially supported by the Science Foundation of Hebei Province (No.502048)
文摘A super-fine compound powder, Ag/SnO_2+La_2O_3+ Bi_2O_3, has been obtainedusing the chemical coprecipitation method. And a new contact material, Ag/SnO_2+La_2O_3+Bi_2O_3, wasproduced by the powder metallurgy method. Its properties are as follows: the density is 9.75-9.93g/cm^3, the resistivity is 2.31-2.55 μΩ ·cm, the hardness is 880-985 MPa. Its mi-crostructureshows that the fine oxides have a uniform distribution in the silver matrix. The results ofmake-break capacity and temperature rise testing show that the new material has better ability ofanti-arc erosion and lower temperature rise than that of commonly used Ag/CdO.
文摘A new silver rare earth oxide contact material, Ag/La2O3(12), was produced by powder metallurgy method. Its performances are as follows: the density is 9.71 similar to 9.96 g.cm(-3); the hardness (HB) is 760 similar to 970 MPa and the resistivity is 2.25 similar to 2.38 mu Omega . cm. The microstructure of Ag/La2O3(12) mas analyzed by SEM and EDS. Rare earth oxide La2O3 shows two shapes, which are uniformly distributed in the form of sphere and abnormality in Ag matrix. La2O3 shows fine spherical shape in the melted area of Ag after laser acting which is used to simulate electric are. The results are contributed to the less splash erosion of Ag. Compared with the main physical and mechanical properties of Ag/SnO2(12) and Ag/CdO(12), the properties of three contact materials are similar, and hence Ag/La2O3(12) may become a potential contact material to be used as the substitute of Ag/CdO(12).
