Vergleichende Untersuchung der Verschleißbilder von Steckverbindern aus Reibverschleiß- und Vibrationsprüfungen mit unterschiedlichen Prüfrichtungen

In this study a comparison between the wear patterns of electrical connectors resulting from two different test types, namely fretting corrosion test and vibration test, is conducted. In both tests, the excitation directions include the mating direction as well as the orthogonal directions corresponding to the mating direction. Different measurement techniques are used to identify similarities and differences between the wear resulting from these test types. The results show fundamentally different critical directions with regard to wear for the respective test types. Furthermore, it is shown that the induced movement of the fretting tests lead to a higher degree of wear than the vibration tests. Also, it is not adequately possible to establish a direct relationship between the induced movement and the excitation amplitude caused by the attached wires since there is a superposition of several movements in the case of real applications.

SOME PARTICULAR ASPECTS OF THE AUTOMOTIVE INDUSTRY CONNECTORS

Electrical connectors are very sensitive parts in an electronic system. The actual meaning of reliability and the problems associated with determining it, are often not right understood. The paper presents some particular aspects of the automotive industry connectors’ i.e. fretting, fretting corrosion prevention, aluminium connections. The performance factors governed by the operating conditions and design-technology factors determined by the manufacturing characteristics of a contact unit were analyzed.

Hydrophobic Dielectric Sealing Material Enabled Highly Reliable Electrical Connectors for Downhole Data and Power Transmission Application

A high-strength dielectric sealing material has been developed for sealing electrical connectors, feedthroughs, bulkheads, and interconnectors. X-ray diffraction analyses have identified that the microstructures of the sealing material could be of amorphous and α-phase mixed morphology, α+β mixed phase, and β-phase dominated tetrahedral microstructure, which primarily depend upon the material processing temperature. The electrical insulation resistance of the β-phase dominated sealing material have nearly two times higher than that of α+β mixed phase sealing material. Both β-phase dominated and α+β mixed phase sealing materials have shown water repelling properties, while amorphous glass phase has shown hydrophilic properties. If a 5,000MΩ insulation resistance is also regarded as baseline for a downhole electrical connector, the maximum operation temperature of α+β mixed phase sealing materials is around 240°C while that of the β-phase dominated sealing material can be up to 300°C. Furthermore, a thermo-mechanical modeling has been developed to quantify if a designed electrical connector has sufficient reliability in the hostile wellbore or downhole environments. The temperature- and pressure-dependent seal compression have suggested that the temperature-related safety factor should be chosen in the range from 2.0 to 5.0 while the pressure-related safety factor should be chosen in the range from 1.5 to 2.0 to ensure 10-20 years electrical connector downhole operating reliability. The qualification tests from prototyped electrical connectors, under 260°C/32,000PSI simulated water-fluid based conditions, have demonstrated that such high-strength sealing material sealed electrical connector could be integrated with logging while drilling (LWD) or/and measurement while drilling (MWD) tools for providing long-term reliable signal, data, and electrical power transmission services, regardless of a water-based or moisture-rich wellbore or/and downhole environment.

INFLUENCE OF CORROSION PROCESSES ON FRICTION AND WEAR OF TIN COATINGS OF WIRE CONNECTORS

The paper describes the results of metallographic, tribological, and microscopic tests of wire connectors. It was shown that the structure and thickness of the tin layer on the copper element varies greatly. The paper describes the results of tribological investigations for electrical connectors in the initial state and covered with a layer of oxides formed as a result of corrosion. The results of tribological tests have shown a great influence of the oxide layer on friction and wear of tin coatings. The results of friction factor measurements were confirmed by microscopic observations. The tests confirmed that the oxide layer reduces plastic deformation of the tin coating and limits its tribological wear. Due to the brittleness and low adhesion of the oxide layer, friction-induced chipping was observed.

Evolution of contact performance of industry electrical connector based on reliability accelerated testing

The evolution of contact performance of electrical connectors, as an expression of service performance, played a significant role in various electronic equipment or system. However, very few methods had been used to detect the evolution of contact performance effectively and accurately. Hence, in this research, reliability accelerated testing was conducted to investigate the evolution of contact performance of electrical connectors. To detect the evolution of contact performance, contact resistance and friction and wear of the connector were measured using a DC resistance tester and an electron microscope respectively. Also, the effect of external conditions such as ambient temperature, mating speed, mating cycles was statistically investigated, and evolution curves were developed for contact resistance and abrasion loss. The obtained results revealed the temperature and mating speed affected the contact performance of electrical connectors. The increment of temperature reduced the shear strength of material and increased the thickness of oxide film. Increased mating speed greatly increased the probability of fracture of micro-protrusion due to collision, the wear form of connector had realized transition from low-speed adhesive wear to high-speed peeling wear. In addition, when the connector was mated about 3000 cycles, the contact performance of the connector would be greatly decreased.

Crosstalk in Electrical Connectors

Crosstalk electromagnetic interference occurs in on-board electrical wire bundles of aircraft electrical systems under the effect of external electromagnetic fields. Efficient reduction of crosstalk and elimination of their propagation paths in wire bundles can be achieved by shielding the conductors in the bundles and the bundles as a whole without breaks and discontinuities between the shields and housings of electrical connectors. The shielding of conductors in bundles does not eliminate the crosstalk completely, which can propagate through the contacts of electrical connectors. For estimating the influence of electrical connectors on the levels of crosstalk in electrical system circuits, their experimental studies should be carried out. In the course of these experimental studies, the interference voltage induced at the receptor contacts when voltage is applied to the source contacts in the specified frequency band is measured. The results from experimental studies of crosstalk for various types of electrical connectors in a specified frequency band make it possible to evaluate the resonance nature and levels of crosstalk interference levels depending on the relative position of the contacts and frequency.

Low-temperature electronic transport of manganese silicide shell-protected single crystal nanowires for nanoelectronics applications

Recently, core-shell nanowires have been proposed as potential electrical connectors for nanoelectronics components. A promising candidate is Mn5Si3 nanowires encapsulated in an oxide shell, due to their low reactivity and...