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Electrically conductive polymer composites have been widely used in recent years. The resistivity of the composites is influenced by several factors. The conductive silicone rubbers (CSRs) were prepared by adding the nickel‐coated graphite (Ni‐G) and/or nickel‐coated carbon fiber (Ni‐CF) into liquid silicon rubbers which were then subjected to the vulcanization. The effect of particle shape and size on the electrical conductivity of CSR was investigated; the results indicate that Ni‐CF filled CSR have lower percolation threshold than Ni‐G filled CSR. Compared to the filled particles with larger size, a higher amount of smaller particles are needed to form the same conductive pathway in CSR. Thus, there are more contact points in conductive pathway, which increase the total contact resistance. The volume resistivity of CSR can be significantly reduced by the doping of Ni‐CF particles, while the effect begins to wear off under high doping content. The fiber‐like Ni‐CF has a good “bridging” function for the formation of conductive pathway in CSR, which is greatly enhanced by increasing the length to diameter (l/d) ratio of Ni‐CF particles. Therefore, doping of the particles that have low percolation threshold can reduce the resistivity of the composites. POLYM. COMPOS., 36:1371–1377, 2015. © 2014 Society of Plastics Engineers

A novel W-Ti self-heating structure was proposed which can generalize a temperature gradient and constant temperature along the metal stripe and can determine the failure location by electrical measurement. The effectiveness of this design is confirmed by different experiments. A metal line resistance method was used to determine the temperature distribution on the metal line. A series of electromigration tests were performed at positive and negative temperature gradient. The results indicate that the negative temperature gradient greatly improved the mean time to failure(MTF) of electromigration, changed the failure location distribution and caused a new tendency of resistance change we called it the "new balance phase".

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Although Al-Cr-N films have excellent oxidation resistance, they also need to have matched mechanical properties. Both the oxidation resistance and mechanical property are essentially determined by microstructure. At present, atomic-scale microstructures of Al-Cr-N films are scarce due to the difficulty of tracing the evolution of nanocrystalline grains, dislocation annihilation and mechanical properties. In this work, atomic-scale structure, phase transformation and dislocation behaviour in Al-Cr-N films were studied by high-resolution transmission electron microscope. The grain size showed no obvious variation when the annealing temperature is lower than 1000°C, but it increased from ∼5 to ∼50 nm when the temperature approached up to 1100°C. Edge dislocations in the deposited films disappeared after the obtained samples were heated. Mechanical properties showed no obvious fluctuations as the temperature was lower than 800°C.