The effect of sliding wear on the rate of surface segregation of sulfur from an OFHC copper sample was investigated. This work was carried out in an ultra-high vacuum system having a residual gas pressure of 5*10/sup -11/ torr. Wear tracks were formed on OFHC Cu that had previously been annealed and argon-ion sputter cleaned. A bent pin was made to slide across the surface with a contact force of 25 g for 9000 cycles. No surface segregation was observed to occur as a result of forming the wear track. Subsequent in situ isothermal annealing between 310 degrees C and 470 degrees C produced S enhancement on the specimen surface. It was observed that the rate of S segregation on the wear track was much faster than off track up to approximately 390 degrees C, where this rate decreased significantly. At higher temperatures, the rate of S segregation on track approximately equaled the off-track rate. The drop in the rate of S segregation on the track at 390 degrees C is interpreted as due to annealing-out of the short-circuit diffusion paths associated with the defects formed when the wear track was made. The subsequent increase in S concentration at higher temperatures is due to the normal surface segregation phenomenon which occurs in annealed samples.<>
{"title":"Enhanced surface segregation in sliding wear tracks","authors":"R. Kothari, R. Vook, J.G. Zhang, M.D. Zhu","doi":"10.1109/HOLM.1989.77914","DOIUrl":"https://doi.org/10.1109/HOLM.1989.77914","url":null,"abstract":"The effect of sliding wear on the rate of surface segregation of sulfur from an OFHC copper sample was investigated. This work was carried out in an ultra-high vacuum system having a residual gas pressure of 5*10/sup -11/ torr. Wear tracks were formed on OFHC Cu that had previously been annealed and argon-ion sputter cleaned. A bent pin was made to slide across the surface with a contact force of 25 g for 9000 cycles. No surface segregation was observed to occur as a result of forming the wear track. Subsequent in situ isothermal annealing between 310 degrees C and 470 degrees C produced S enhancement on the specimen surface. It was observed that the rate of S segregation on the wear track was much faster than off track up to approximately 390 degrees C, where this rate decreased significantly. At higher temperatures, the rate of S segregation on track approximately equaled the off-track rate. The drop in the rate of S segregation on the track at 390 degrees C is interpreted as due to annealing-out of the short-circuit diffusion paths associated with the defects formed when the wear track was made. The subsequent increase in S concentration at higher temperatures is due to the normal surface segregation phenomenon which occurs in annealed samples.<<ETX>>","PeriodicalId":441734,"journal":{"name":"Proceedings of the Thirty Fifth Meeting of the IEEE Holm Conference on Electrical Contacts","volume":"10 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":"132407720","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 behavior of vacuum-circuit-breaker (VCB) contacts related directly to arc extinction in the arc current-zero region dominates the postarc dielectric recovery. The practical dielectric recovery processes were investigated to determine the role of VCB contacts in this process. Experiments show that the process can be divided into two stages. In the earlier stage, the sheath near the contact surface produced by recovery voltage is dominant. Arcing history expressed by the ion energy also plays a role. In the later stage, contact erosion, surface deformation, and background pressure are important factors. For comparison, free-dielectric recovery was measured with the same sample conditions but without recovery voltage. The results of this work clarify the comprehensive pattern of the practical dielectric recovery phenomena of vacuum arcs.<>
{"title":"Role of vacuum interrupter contacts in dielectric recovery phenomena","authors":"Cheng Li-chun, Zai Ji-Yan, Qin Hongsan","doi":"10.1109/HOLM.1989.77948","DOIUrl":"https://doi.org/10.1109/HOLM.1989.77948","url":null,"abstract":"The behavior of vacuum-circuit-breaker (VCB) contacts related directly to arc extinction in the arc current-zero region dominates the postarc dielectric recovery. The practical dielectric recovery processes were investigated to determine the role of VCB contacts in this process. Experiments show that the process can be divided into two stages. In the earlier stage, the sheath near the contact surface produced by recovery voltage is dominant. Arcing history expressed by the ion energy also plays a role. In the later stage, contact erosion, surface deformation, and background pressure are important factors. For comparison, free-dielectric recovery was measured with the same sample conditions but without recovery voltage. The results of this work clarify the comprehensive pattern of the practical dielectric recovery phenomena of vacuum arcs.<<ETX>>","PeriodicalId":441734,"journal":{"name":"Proceedings of the Thirty Fifth Meeting of the IEEE Holm Conference on Electrical Contacts","volume":"22 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":"131298345","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. The purpose of this presentation was to identify and discuss the connector requirements in regards to the following: (1) assembly methods/exposures (manual/robotic placement, ease of location, polarization, retention methods, and lead tolerances/planarity); (2) assembly process compatibility (solder process time/temperature profiles, chemical exposures, and mechanical parameters); (3) repair process methods of removal and replacement; (4) quality control (manual/visual inspection, electrical shorts/open testing, and insulation resistance testing); and (5) connector contact resistance stability (initial, time dependent, and recovery).<>
{"title":"Requirements to achieve connector and printed circuit assembly quality","authors":"W. Emmons","doi":"10.1109/HOLM.1989.77924","DOIUrl":"https://doi.org/10.1109/HOLM.1989.77924","url":null,"abstract":"Summary form only given. The purpose of this presentation was to identify and discuss the connector requirements in regards to the following: (1) assembly methods/exposures (manual/robotic placement, ease of location, polarization, retention methods, and lead tolerances/planarity); (2) assembly process compatibility (solder process time/temperature profiles, chemical exposures, and mechanical parameters); (3) repair process methods of removal and replacement; (4) quality control (manual/visual inspection, electrical shorts/open testing, and insulation resistance testing); and (5) connector contact resistance stability (initial, time dependent, and recovery).<<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":"134280471","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}
Two types of sleeve connector (crimp and solder) used in aluminum cable splices were examined after being tested in a series of accelerated aging experiments. Diagnostic techniques, such as optical microscopy, scanning electron microscopy, and energy dispersive X-ray analysis, were applied to reveal the microstructure of the contact. The observation correlates well with the measurements of the contact resistance. Corrective measures are suggested to improve the performance of the cable splices.<>
{"title":"Metallurgic and contact resistance studies of sleeve connectors in aluminium cable splices","authors":"C. Dang, M. Braunovic","doi":"10.1109/HOLM.1989.77944","DOIUrl":"https://doi.org/10.1109/HOLM.1989.77944","url":null,"abstract":"Two types of sleeve connector (crimp and solder) used in aluminum cable splices were examined after being tested in a series of accelerated aging experiments. Diagnostic techniques, such as optical microscopy, scanning electron microscopy, and energy dispersive X-ray analysis, were applied to reveal the microstructure of the contact. The observation correlates well with the measurements of the contact resistance. Corrective measures are suggested to improve the performance of the cable splices.<<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":"133622281","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}
A mechanism for the degeneration of stationary electrical contacts is proposed. The mechanism derives from Mullins' model (1959) of flattening of free surfaces through the action of capillarity forces. Mass transport for surface deformation is assumed to occur through volume self-diffusion and is calculated on the basis of diffusion constants characteristic of plastically deformed or mechanically stressed aluminium. A simple electrical contact model suggests that the increase in contact resistance stemming from surface flattening in Al at room temperature can become noticeable in a time interval of a few days ( approximately 10/sup 6/ s). This result may explain the deterioration of contaminated Al/Al stationary electrical contacts operated at room temperature, after run-times of 10/sup 5/-10/sup 6/ s. Finally, since many metals are characterized both by rapid volume or surface diffusion and by a large surface energy, the results suggest that asperity flattening can lead to degeneration in all bulk electrical interfaces.<>
{"title":"A possible degeneration mechanism in stationary electrical contacts","authors":"R. Timsit","doi":"10.1109/HOLM.1989.77940","DOIUrl":"https://doi.org/10.1109/HOLM.1989.77940","url":null,"abstract":"A mechanism for the degeneration of stationary electrical contacts is proposed. The mechanism derives from Mullins' model (1959) of flattening of free surfaces through the action of capillarity forces. Mass transport for surface deformation is assumed to occur through volume self-diffusion and is calculated on the basis of diffusion constants characteristic of plastically deformed or mechanically stressed aluminium. A simple electrical contact model suggests that the increase in contact resistance stemming from surface flattening in Al at room temperature can become noticeable in a time interval of a few days ( approximately 10/sup 6/ s). This result may explain the deterioration of contaminated Al/Al stationary electrical contacts operated at room temperature, after run-times of 10/sup 5/-10/sup 6/ s. Finally, since many metals are characterized both by rapid volume or surface diffusion and by a large surface energy, the results suggest that asperity flattening can lead to degeneration in all bulk electrical interfaces.<<ETX>>","PeriodicalId":441734,"journal":{"name":"Proceedings of the Thirty Fifth Meeting of the IEEE Holm Conference on Electrical Contacts","volume":"149 1 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":"122456933","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. Electrical connectors are passive devices that interconnect circuit elements through low-resistance stationary contacts. For an electronic system to perform reliably, the interconnect system must be reliable in the environment and throughout the expected life of the system. It is noted that building reliability and quality into an electrical interconnect system is a very complex process that depends on systematically addressing these issues at every step of the development cycle through the initial production phase. The major steps in the development cycle through initial production were reviewed with regard to reliability and quality. This included topics such as system requirements, contact physics considerations, product design, tool build, initial production, qualification testing, and process control. In addition, an attempt was made to define the number of variables involved in defining requirements, specifying designs, manufacturing products, and controlling the processes involved in producing and maintaining quality products.<>
{"title":"Overview: connector contact quality","authors":"R. Malucci","doi":"10.1109/HOLM.1989.77923","DOIUrl":"https://doi.org/10.1109/HOLM.1989.77923","url":null,"abstract":"Summary form only given. Electrical connectors are passive devices that interconnect circuit elements through low-resistance stationary contacts. For an electronic system to perform reliably, the interconnect system must be reliable in the environment and throughout the expected life of the system. It is noted that building reliability and quality into an electrical interconnect system is a very complex process that depends on systematically addressing these issues at every step of the development cycle through the initial production phase. The major steps in the development cycle through initial production were reviewed with regard to reliability and quality. This included topics such as system requirements, contact physics considerations, product design, tool build, initial production, qualification testing, and process control. In addition, an attempt was made to define the number of variables involved in defining requirements, specifying designs, manufacturing products, and controlling the processes involved in producing and maintaining quality products.<<ETX>>","PeriodicalId":441734,"journal":{"name":"Proceedings of the Thirty Fifth Meeting of the IEEE Holm Conference on Electrical Contacts","volume":"18 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":"123956148","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}
T. Yokokawa, T. Yano, C. Kawakita, K. Hinohara, T. Kobayashi
A precise analysis of ruthenium-plated contact surfaces was made to obtain information on the thickness of ruthenium oxide film. The thickness of ruthenium oxide film before and after high-temperature oxygen treatment was measured. As a result of investigation using ellipsometry and Auger electron spectroscopy, it was found that the thickness of ruthenium oxide film on the ruthenium-plated contact surface treated with oxygen at 450 degrees C optimum treatment temperature is approximately 50 AA and that the thickness increases as treatment temperature rises.<>
{"title":"Thickness of ruthenium oxide film produced by the surface deactivation treatment of ruthenium-plated contact reed switches","authors":"T. Yokokawa, T. Yano, C. Kawakita, K. Hinohara, T. Kobayashi","doi":"10.1109/HOLM.1989.77937","DOIUrl":"https://doi.org/10.1109/HOLM.1989.77937","url":null,"abstract":"A precise analysis of ruthenium-plated contact surfaces was made to obtain information on the thickness of ruthenium oxide film. The thickness of ruthenium oxide film before and after high-temperature oxygen treatment was measured. As a result of investigation using ellipsometry and Auger electron spectroscopy, it was found that the thickness of ruthenium oxide film on the ruthenium-plated contact surface treated with oxygen at 450 degrees C optimum treatment temperature is approximately 50 AA and that the thickness increases as treatment temperature rises.<<ETX>>","PeriodicalId":441734,"journal":{"name":"Proceedings of the Thirty Fifth Meeting of the IEEE Holm Conference on Electrical Contacts","volume":"191 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":"122979846","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 degradation of aluminum-to-tin plated electrical connections under fretting conditions has been studied. In addition to contact resistance measurements, scanning electron microscopy (SEM) and X-ray fluorescence (EDX) analysis were used to study the processes involved. It was shown that fretting adversely affects the contact resistance of aluminum-to-tin plated connections, which show a rapid increase and substantial fluctuations after prolonged exposure to fretting. Two sustained plateaus in the contact resistance characteristics were observed: one coinciding with the melting voltage of tin and aluminum, and the other in the range corresponding to the voltage range of the melting, sublimation, and decomposition of the oxides and vaporization of contact materials. The effects of fretting were reduced significantly by applying higher contact loads. SEM and EDX analyses revealed that considerable damage of the contact zones resulted from the fretting action and substantial exchange of material occurred.<>
{"title":"Effect of fretting in aluminium-to-tin connections","authors":"M. Braunovic","doi":"10.1109/HOLM.1989.77943","DOIUrl":"https://doi.org/10.1109/HOLM.1989.77943","url":null,"abstract":"The degradation of aluminum-to-tin plated electrical connections under fretting conditions has been studied. In addition to contact resistance measurements, scanning electron microscopy (SEM) and X-ray fluorescence (EDX) analysis were used to study the processes involved. It was shown that fretting adversely affects the contact resistance of aluminum-to-tin plated connections, which show a rapid increase and substantial fluctuations after prolonged exposure to fretting. Two sustained plateaus in the contact resistance characteristics were observed: one coinciding with the melting voltage of tin and aluminum, and the other in the range corresponding to the voltage range of the melting, sublimation, and decomposition of the oxides and vaporization of contact materials. The effects of fretting were reduced significantly by applying higher contact loads. SEM and EDX analyses revealed that considerable damage of the contact zones resulted from the fretting action and substantial exchange of material occurred.<<ETX>>","PeriodicalId":441734,"journal":{"name":"Proceedings of the Thirty Fifth Meeting of the IEEE Holm Conference on Electrical Contacts","volume":"41 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":"121616691","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. This workshop addresses the issue of how quality is built into modern electronics interconnect systems. The primary focus is on the question of quality in manufacturing and using connector contacts. A brief systems overview of the various elements in the development cycle related to building quality into modern electronics systems is provided. This is followed by short presentations from two users and two manufacturers which addresses questions such as What do users want and how do they define requirements? and How do connector manufacturers achieve these quality goals in practice? Attention is given to a wide range of issues such as application requirements, the design cycle, initial production, and product qualification. Quality requirements and process control are discussed.<>
{"title":"How to achieve quality in the manufacturing of connector contacts","authors":"R. Malucci","doi":"10.1109/HOLM.1989.77922","DOIUrl":"https://doi.org/10.1109/HOLM.1989.77922","url":null,"abstract":"Summary form only given. This workshop addresses the issue of how quality is built into modern electronics interconnect systems. The primary focus is on the question of quality in manufacturing and using connector contacts. A brief systems overview of the various elements in the development cycle related to building quality into modern electronics systems is provided. This is followed by short presentations from two users and two manufacturers which addresses questions such as What do users want and how do they define requirements? and How do connector manufacturers achieve these quality goals in practice? Attention is given to a wide range of issues such as application requirements, the design cycle, initial production, and product qualification. Quality requirements and process control are discussed.<<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":"115421020","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}
Transient contacts, such as those in railgun armatures, operate near the limits of metal-metal contacts. When the current-carrying limit of a contact is exceeded, the contact makes a transition from a low-voltage state (typically less than 1 V) to an arc with high-voltage (typically 30 V or greater) and leads to high erosion of the slider and substrate. Experiments were performed on metal contacts at current densities typical of railgun armatures (>1 GA/m/sup 2/). It was found that the classical theory of electrical contacts did not support observations. A theoretical description to support the experimental observations was developed. The theoretical concept is based on the assumption that, under the experimental conditions considered, the contact is adiabatic. Transition of the contact then depends on resistive heating of the contact area. A computer simulation predicts when the contact will make the transition to arcing. It is suggested that a contact should be made with a material with a high action to vaporize, such as copper. Since the contact is adiabatic, only the contactor surface zone is critical.<>
{"title":"Contact current carrying limits","authors":"J. Barber, L. Thurmond","doi":"10.1109/HOLM.1989.77915","DOIUrl":"https://doi.org/10.1109/HOLM.1989.77915","url":null,"abstract":"Transient contacts, such as those in railgun armatures, operate near the limits of metal-metal contacts. When the current-carrying limit of a contact is exceeded, the contact makes a transition from a low-voltage state (typically less than 1 V) to an arc with high-voltage (typically 30 V or greater) and leads to high erosion of the slider and substrate. Experiments were performed on metal contacts at current densities typical of railgun armatures (>1 GA/m/sup 2/). It was found that the classical theory of electrical contacts did not support observations. A theoretical description to support the experimental observations was developed. The theoretical concept is based on the assumption that, under the experimental conditions considered, the contact is adiabatic. Transition of the contact then depends on resistive heating of the contact area. A computer simulation predicts when the contact will make the transition to arcing. It is suggested that a contact should be made with a material with a high action to vaporize, such as copper. Since the contact is adiabatic, only the contactor surface zone is critical.<<ETX>>","PeriodicalId":441734,"journal":{"name":"Proceedings of the Thirty Fifth Meeting of the IEEE Holm Conference on Electrical Contacts","volume":"44 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":"126549168","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}
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