Electrode erosion was measured under conditions of practical high current and axial magnetic field (AMF). Arc interruptions were made in a demountable vacuum chamber. Electrode erosion was assessed by weighting. It is shown that the rate of electrode erosion with AMF is 39.8 mu g/C and that without AMF it is 1.3 mg/C; the anode gains 15 mu g/C for diffused arcs.<>
在实际大电流和轴向磁场(AMF)条件下测量了电极的腐蚀。电弧中断是在可拆卸的真空室中进行的。电极侵蚀通过加权评估。结果表明，有AMF的电极腐蚀速率为39.8 mu g/C，无AMF的电极腐蚀速率为1.3 mg/C;扩散电弧的阳极增益为15 μ g/C。
{"title":"Electrode erosion under high current vacuum arcs","authors":"Z. Jiyan, Cheng Lichun","doi":"10.1109/HOLM.1989.77947","DOIUrl":"https://doi.org/10.1109/HOLM.1989.77947","url":null,"abstract":"Electrode erosion was measured under conditions of practical high current and axial magnetic field (AMF). Arc interruptions were made in a demountable vacuum chamber. Electrode erosion was assessed by weighting. It is shown that the rate of electrode erosion with AMF is 39.8 mu g/C and that without AMF it is 1.3 mg/C; the anode gains 15 mu g/C for diffused arcs.<<ETX>>","PeriodicalId":441734,"journal":{"name":"Proceedings of the Thirty Fifth Meeting of the IEEE Holm Conference on Electrical Contacts","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121649330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Friction, wear, and resistivity are reported for monolithic glassy carbon and a composite made of copper fibers in a glassy carbon matrix. Reduction of atmospheric oxygen is shown to reduce the wear rate for both of the materials, thereby indicating that the contact behavior is different from that of graphite. Repeats of earlier measurements of tribological behavior of glassy carbon on glassy carbon confirm the low wear rate reported previously and show marked lowering of the friction coefficient in a long run (724 km or sliding).<>
{"title":"Friction and wear experiments on glassy carbon based materials","authors":"R. A. Burton, R. G. Burton","doi":"10.1109/HOLM.1989.77917","DOIUrl":"https://doi.org/10.1109/HOLM.1989.77917","url":null,"abstract":"Friction, wear, and resistivity are reported for monolithic glassy carbon and a composite made of copper fibers in a glassy carbon matrix. Reduction of atmospheric oxygen is shown to reduce the wear rate for both of the materials, thereby indicating that the contact behavior is different from that of graphite. Repeats of earlier measurements of tribological behavior of glassy carbon on glassy carbon confirm the low wear rate reported previously and show marked lowering of the friction coefficient in a long run (724 km or sliding).<<ETX>>","PeriodicalId":441734,"journal":{"name":"Proceedings of the Thirty Fifth Meeting of the IEEE Holm Conference on Electrical Contacts","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124161365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The early field failure of some motor control contactors due to the separation of the contacts from the copper arms to which they had been brazed was investigated. All of the failed devices were from geographical areas where the temperature and humidity were high and where there was a local source of sulfurous gases. Corrosion of the contact assemblies in the area of their braze joints by sulfur was identified as the cause of the premature failures. A laboratory test was used to evaluate the effectiveness of different assembly modifications in minimizing the corrosive attack by hydrogen sulfide. Silver plating was ineffective in protecting the braze joint from corrosion. Changing the braze alloy to one having a substantial zinc content was found to effectively impede the corrosive attack of the braze joint area and thus would be expected to increase the life of the devices in corrosive sulfurous environments.<>
{"title":"Corrosion of braze joints by hydrogen sulfide","authors":"P. Wingert, C. Leung","doi":"10.1109/HOLM.1989.77921","DOIUrl":"https://doi.org/10.1109/HOLM.1989.77921","url":null,"abstract":"The early field failure of some motor control contactors due to the separation of the contacts from the copper arms to which they had been brazed was investigated. All of the failed devices were from geographical areas where the temperature and humidity were high and where there was a local source of sulfurous gases. Corrosion of the contact assemblies in the area of their braze joints by sulfur was identified as the cause of the premature failures. A laboratory test was used to evaluate the effectiveness of different assembly modifications in minimizing the corrosive attack by hydrogen sulfide. Silver plating was ineffective in protecting the braze joint from corrosion. Changing the braze alloy to one having a substantial zinc content was found to effectively impede the corrosive attack of the braze joint area and thus would be expected to increase the life of the devices in corrosive sulfurous environments.<<ETX>>","PeriodicalId":441734,"journal":{"name":"Proceedings of the Thirty Fifth Meeting of the IEEE Holm Conference on Electrical Contacts","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133346824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Experimental data are analyzed for carbon block sliding on the surface of a metal disk. Conduction measurements suggest that the constriction resistance is much lower than expected for a contact area that is controlled by the hardness of the carbon. Analysis of heat transfer over a range of sliding speeds supports the idea of a thermoelastic phenomenon which leads to concentration of load on the peak of a single thermal asperity. The contact area predicted by this analysis is considerably larger than that predicted by plastic yielding of the asperities in accord with classical contact theory. The single-asperity model leads to an upper bound of predicted temperature, and this is found to be moderate over a large range of sliding speeds at loads comparable to those used on brushes.<>
{"title":"Experiments and analysis of the thermoelastic behavior of a brush on a slipring","authors":"R. A. Burton, R. G. Burton","doi":"10.1109/HOLM.1989.77916","DOIUrl":"https://doi.org/10.1109/HOLM.1989.77916","url":null,"abstract":"Experimental data are analyzed for carbon block sliding on the surface of a metal disk. Conduction measurements suggest that the constriction resistance is much lower than expected for a contact area that is controlled by the hardness of the carbon. Analysis of heat transfer over a range of sliding speeds supports the idea of a thermoelastic phenomenon which leads to concentration of load on the peak of a single thermal asperity. The contact area predicted by this analysis is considerably larger than that predicted by plastic yielding of the asperities in accord with classical contact theory. The single-asperity model leads to an upper bound of predicted temperature, and this is found to be moderate over a large range of sliding speeds at loads comparable to those used on brushes.<<ETX>>","PeriodicalId":441734,"journal":{"name":"Proceedings of the Thirty Fifth Meeting of the IEEE Holm Conference on Electrical Contacts","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125404865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Long-time service data as well as data from current cycle testing on electrical contact resistance have been analyzed with respect to mechanical design parameters. The importance of the pressure distribution over the contact surface was studied for a constant surface force. The mechanical stresses acting over the contact surface have been calculated by the finite-element method for the type of contact investigated. It is found that a high specific contact pressure promotes lower contact resistance and favors their long-time stability. The pressure distribution on the contact surface has a significant influence on the aging properties of the connectors studied. It was confirmed that the aging behavior is strongly affected by the preparation methods. The aging mechanisms detected on the contact surfaces studied are fretting and formation of intermetallic phases.<>
{"title":"Influence of mechanical design parameters on electrical contact performance","authors":"Karl-Erik Olsson, A. Oberg","doi":"10.1109/HOLM.1989.77932","DOIUrl":"https://doi.org/10.1109/HOLM.1989.77932","url":null,"abstract":"Long-time service data as well as data from current cycle testing on electrical contact resistance have been analyzed with respect to mechanical design parameters. The importance of the pressure distribution over the contact surface was studied for a constant surface force. The mechanical stresses acting over the contact surface have been calculated by the finite-element method for the type of contact investigated. It is found that a high specific contact pressure promotes lower contact resistance and favors their long-time stability. The pressure distribution on the contact surface has a significant influence on the aging properties of the connectors studied. It was confirmed that the aging behavior is strongly affected by the preparation methods. The aging mechanisms detected on the contact surfaces studied are fretting and formation of intermetallic phases.<<ETX>>","PeriodicalId":441734,"journal":{"name":"Proceedings of the Thirty Fifth Meeting of the IEEE Holm Conference on Electrical Contacts","volume":"111 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116572480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The authors have developed a holographic pattern measuring system (HPMS) which combines the techniques of holography and graphic image processing. The HPMS was applied to the study of the thermal deformation of a contact spring. Using this approach, the microscopic displacement of the contact spring could be quantitatively measured in a noncontact way, and the distribution of the displacement could be shown automatically as a three-dimensional graphic image. In the case of thermal excitation by the current flow through the electric contact, a quantitative correlation between the slide of the contact point and the thermal deformation of the contact spring was obtained. In addition, the authors found some irregularity in contact voltage when the current flowed through the closing contacts. From the deformation analysis of the contact spring, the relationship between the contact voltage and the deformation of the contact spring due to current flow was made clear.<>
{"title":"A holographic measurement of microscopical sliding of electrical contact due to contact spring thermal deformation","authors":"M. Taniguchi, H. Sone, T. Takagi","doi":"10.1109/HOLM.1989.77946","DOIUrl":"https://doi.org/10.1109/HOLM.1989.77946","url":null,"abstract":"The authors have developed a holographic pattern measuring system (HPMS) which combines the techniques of holography and graphic image processing. The HPMS was applied to the study of the thermal deformation of a contact spring. Using this approach, the microscopic displacement of the contact spring could be quantitatively measured in a noncontact way, and the distribution of the displacement could be shown automatically as a three-dimensional graphic image. In the case of thermal excitation by the current flow through the electric contact, a quantitative correlation between the slide of the contact point and the thermal deformation of the contact spring was obtained. In addition, the authors found some irregularity in contact voltage when the current flowed through the closing contacts. From the deformation analysis of the contact spring, the relationship between the contact voltage and the deformation of the contact spring due to current flow was made clear.<<ETX>>","PeriodicalId":441734,"journal":{"name":"Proceedings of the Thirty Fifth Meeting of the IEEE Holm Conference on Electrical Contacts","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130283701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Summary form only given, as follows. Achieving quality in the manufacture of connector contacts begins with a complete understanding of the performance requirements of the customer's system (including environmental, mechanical, electrical, technological, and reliability requirements) before the contact design is begun. Ensuring conformance to these requirements by the completed connector configuration starts with the initial design and continues through a carefully controlled design review system from concept to the high-volume manufacturing stage. Carefully written inspection plans, process capability studies, process controls, and continuous measurement of PPM rejection rates for all phases of the manufacturing process (including stamping, machining, plating, and assembly) will provide a contact that performs as required. Part of the quality process must be an understanding that goals must be set for continuous improvement and reject reduction.<>
{"title":"Achieving quality in the manufacture of connector contacts","authors":"R. Hartwell","doi":"10.1109/HOLM.1989.77927","DOIUrl":"https://doi.org/10.1109/HOLM.1989.77927","url":null,"abstract":"Summary form only given, as follows. Achieving quality in the manufacture of connector contacts begins with a complete understanding of the performance requirements of the customer's system (including environmental, mechanical, electrical, technological, and reliability requirements) before the contact design is begun. Ensuring conformance to these requirements by the completed connector configuration starts with the initial design and continues through a carefully controlled design review system from concept to the high-volume manufacturing stage. Carefully written inspection plans, process capability studies, process controls, and continuous measurement of PPM rejection rates for all phases of the manufacturing process (including stamping, machining, plating, and assembly) will provide a contact that performs as required. Part of the quality process must be an understanding that goals must be set for continuous improvement and reject reduction.<<ETX>>","PeriodicalId":441734,"journal":{"name":"Proceedings of the Thirty Fifth Meeting of the IEEE Holm Conference on Electrical Contacts","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126588514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Experiments were conducted to determine the switching performance of Ag-W contacts when operated in combination with Ag-(Sn,In)O and Ag-SnO/sub 2/ materials. Contact pairs for each combination were evaluated in an experimental actuator at a current of 150 A. The Ag-W contact was always the moving contact. The experimental procedure consisted of the following steps: (1) the new contacts were closed, a steady current of 150 A was passed, and the voltage drop (V/sub c/) across the contacts and the temperature rise (T/sub r/) of the back of the fixed contact were measured; and (2) the contacts then switched a 150-A, 600-V (rms) circuit for 2000 operations. After this, step (1) was repeated. Both the Ag-W vs. Ag-(Sn,In)O and the Ag-W vs. Ag-SnO/sub 2/ contact pairs gave low values of V/sub c/ when new, a characteristics of good Ag-to-Ag contact. After 2000 operations the V/sub c/ values for both contact combinations were very high and variable. Metallurgical examination of the contacts showed arc-resistant, oxide surfaces containing complex oxides of Ag, Sn, and In alloys as well as complex tungstates formed from combinations of Ag, Sn, and In.<>
{"title":"Switching performance of AgW-Ag(Sn,In)O and AgW-AgSnO/sub 2/ contact pairs","authors":"P. Slade, Y. Chien, J.A. Bindas","doi":"10.1109/HOLM.1989.77906","DOIUrl":"https://doi.org/10.1109/HOLM.1989.77906","url":null,"abstract":"Experiments were conducted to determine the switching performance of Ag-W contacts when operated in combination with Ag-(Sn,In)O and Ag-SnO/sub 2/ materials. Contact pairs for each combination were evaluated in an experimental actuator at a current of 150 A. The Ag-W contact was always the moving contact. The experimental procedure consisted of the following steps: (1) the new contacts were closed, a steady current of 150 A was passed, and the voltage drop (V/sub c/) across the contacts and the temperature rise (T/sub r/) of the back of the fixed contact were measured; and (2) the contacts then switched a 150-A, 600-V (rms) circuit for 2000 operations. After this, step (1) was repeated. Both the Ag-W vs. Ag-(Sn,In)O and the Ag-W vs. Ag-SnO/sub 2/ contact pairs gave low values of V/sub c/ when new, a characteristics of good Ag-to-Ag contact. After 2000 operations the V/sub c/ values for both contact combinations were very high and variable. Metallurgical examination of the contacts showed arc-resistant, oxide surfaces containing complex oxides of Ag, Sn, and In alloys as well as complex tungstates formed from combinations of Ag, Sn, and In.<<ETX>>","PeriodicalId":441734,"journal":{"name":"Proceedings of the Thirty Fifth Meeting of the IEEE Holm Conference on Electrical Contacts","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132902649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Recent experimental work on aluminium contact interfaces carrying direct current suggests that the electric current itself can be responsible for degradation of the contact spots. Scanning electron microscopy studies of the metallurgy inside the minute conducting areas support this conclusion. The high current densities and the high temperature in the contact zones cause a mass transport by electromigration. This mass flow through the interface is a nonstationary process, leading to an accumulation of vacancies cluster and form voids and cavities, and the electrical conductivity is gradually reduced. Eventually, the contact spot is so heavily degraded that it is unable to pass the high current densities, and new current paths are created in the vicinity of the original spot. This can be considered as an intrinsic aging mechanism. In contrast to all other degradation processes, the current itself, i.e. the flow of electrons, is found to impair the electrical properties of the contact spot directly.<>
{"title":"Current-induced aging of contact spots","authors":"M. Runde, E. Hodne, B. Tøtdal","doi":"10.1109/HOLM.1989.77942","DOIUrl":"https://doi.org/10.1109/HOLM.1989.77942","url":null,"abstract":"Recent experimental work on aluminium contact interfaces carrying direct current suggests that the electric current itself can be responsible for degradation of the contact spots. Scanning electron microscopy studies of the metallurgy inside the minute conducting areas support this conclusion. The high current densities and the high temperature in the contact zones cause a mass transport by electromigration. This mass flow through the interface is a nonstationary process, leading to an accumulation of vacancies cluster and form voids and cavities, and the electrical conductivity is gradually reduced. Eventually, the contact spot is so heavily degraded that it is unable to pass the high current densities, and new current paths are created in the vicinity of the original spot. This can be considered as an intrinsic aging mechanism. In contrast to all other degradation processes, the current itself, i.e. the flow of electrons, is found to impair the electrical properties of the contact spot directly.<<ETX>>","PeriodicalId":441734,"journal":{"name":"Proceedings of the Thirty Fifth Meeting of the IEEE Holm Conference on Electrical Contacts","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134440204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Corrosive gas environmental tests are used to predict the reliability of electrical connectors used in data system products under conditions found in business office environments. A corrosive gaseous environmental acceleration test called G1(T) is evaluated through variations in testing conditions, in particular for those which differ from outside testing standards used in the connector industry. An investigation of those features of various acceleration tests which could be recommended for adoption into an industry-wide testing standard are reported. These studies could be important for gaining a consensus for support of an acceleration testing practice to predict corrosion reliability during the life of a product. Copper, nickel, and porous gold coupons (electroplated gold over nickel over copper) are used to determine the effects of each corrosive gas test environment. The corrosion of copper is quantified by coulometric reduction, while nickel is evaluated by energy dispersive X-ray fluorescence analysis. The porous gold coupons are visually examined for the presence of pore and creep corrosion, which makes it possible to determine the degree of environmental exposure quickly.<>
{"title":"Corrosive gas environmental testing for electrical contacts","authors":"R. Gore, R. Witska, J. R. Kirby, J. Chao","doi":"10.1109/HOLM.1989.77931","DOIUrl":"https://doi.org/10.1109/HOLM.1989.77931","url":null,"abstract":"Corrosive gas environmental tests are used to predict the reliability of electrical connectors used in data system products under conditions found in business office environments. A corrosive gaseous environmental acceleration test called G1(T) is evaluated through variations in testing conditions, in particular for those which differ from outside testing standards used in the connector industry. An investigation of those features of various acceleration tests which could be recommended for adoption into an industry-wide testing standard are reported. These studies could be important for gaining a consensus for support of an acceleration testing practice to predict corrosion reliability during the life of a product. Copper, nickel, and porous gold coupons (electroplated gold over nickel over copper) are used to determine the effects of each corrosive gas test environment. The corrosion of copper is quantified by coulometric reduction, while nickel is evaluated by energy dispersive X-ray fluorescence analysis. The porous gold coupons are visually examined for the presence of pore and creep corrosion, which makes it possible to determine the degree of environmental exposure quickly.<<ETX>>","PeriodicalId":441734,"journal":{"name":"Proceedings of the Thirty Fifth Meeting of the IEEE Holm Conference on Electrical Contacts","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116348365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：