The melting and solidification behaviors of (SiO2),o~,Pbx sputtered films, where nanoscale Pb particles are embedded in amorphous SiO~ matrix, were studied using differential scanning calorimetry (DSC) and transmission electron microscopy (TEM). With decreasing the size of Pb particles, lowering of the melting point and the degree of supercooling of Pb particles were significantly increased. A very large thermal hysteresis loop width of 213K, that is, the depression of the melting point and the increase of supercooling of Pb particles with a diameter of 5nm was as large as 63K and 150K, respectively, was observed by DSC. These results were discussed in a phenomenological context considering the existence of the interface between Pb particles and amorphous SiO~. matrix. The depression of the melting point of Pb particles is due to the increase in the interfacial energy between fine Pb particles and amorphous SiO2 matrix. A large supercooling of Pb particles is interpreted as a heterogeneous nucleation process due to nearly impurit3'-free free particles.

The reheating behavior of 50 vol.% SiCp/Al squeeze casting composite was investigated at temperatures ranging from 600 o C to 900 o C using XRD and SEM techniques from the microstructural point of view. It was found that SiCp/Al composite could hold its original shape while being reheated at temperatures elevated even far above the melting temperature of pure Al. The high volume fraction of SiC reinforcement, which would restrict the fluidity of molten Al matrix and the reconfiguration of SiC particles during the reheating of SiCp/ Al composite, was thought to be responsible for the "remelting resistance" of the SiCp/Al composite. The extent of the reaction between the SiC particles and molten Al was found to increase with increased reheating temperature. From the viewpoint of controlling the formation of aluminum carbide, reheating temperature either for recycling or for remelting processing of the SiCp/Al composite, a temperature lower than 750 o C would be better. Despite its being unfavorable to remelting or recycling processing, the remelting resistance of the SiCp/Al composite with high volume fraction reinforcement is attractive for thermal function and high temperature applications.

Forest fire can cause a serious damage to overhead conductors. Therefore, detailed investigation on the changes of mechanical and electrical properties of damaged conductors should be carried out to understand the effect of forest fires on conductors. This is of critical importance in maintaining transmission line safely. This paper examines the changes of mechanical and electrical properties of flame exposed conductor. Tensile strength (TS) decreased according to increase of forest fire temperature and conductivity changed according to forest fire temperature. Specimens were aluminum conductors of aluminium conductor steel reinforced (ACSR) 410, 240, 480 ㎟. In this paper, the electrical and mechanical characteristics of forest fires exposed overhead conductors depending on the diameter of aluminum conductors are presented. It was possible to estimate the degree of deterioration caused by forest fires. The detailed results are given in the paper.

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Abstract:The new recycling technology for aged Aluminum wires in overhead conductor have been carried out. We are attempting to develop remanufacturing method for them for more effective way of recycling in stead of its conventional remelting process. The weld of aged aluminum wires play a vital role in remanufacture process. The paper investigates the mechanical properties during cold welding process of aged Aluminum wire. The tensile tests and microscopic analysis results are discussed to underscore the hardening features of welded aluminum wire. Various graphs are presented accompanied by discussion about their relevance on the process.