The ethanol flame was successfully used to synthesize highly graphitic hollow-cored carbon nanotubes (CNTs) and novel disorder solidcored carbon nanofibers (CNFs). Their morphologies were characterized by using scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy and Raman spectroscopy. It was found that the mixture of CNTs and CNFs were grown on Ni-contained substrates, whereas only the CNFs were produced on carbon steel and low alloy steel substrates. It has been established that Ni and its compounds play a key role in CNTs growth and Fe and its compounds in CNFs growth. The models of 'hollowcored mechanism' and 'solid-cored mechanism' were proposed to explain the present CNTs and CNFs formations, based on the theory that 'Fe has a strong affinity for carbon and Ni has a weak affinity for carbon'. It is expected that the present ethanol flame may provide a much simpler and more economic approach for mass-production of CNTs and CNFs by using large flame or multi-flames.

Different functionally graded 20 wt.% MgO-ZrO2yNiCrAl thermal barrier coatings were obtained through the plasma spraying process. The microstructures, chemical compositions and fractured surface were examined by means of electron probe microscopic analysis (EPMA), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The SEM and EPMA results showed that: (1) microstructures and compositions varied gradually in the coatings; (2) the elements Cr and Al were enriched along the sprayed lamellae boundaries and leaded to the formation of oxides. TEM observation enabled finding the formation of dense dislocations and deformation twins, and also the formation of the oxides Al2O3 and Cr2O3 between grain boundaries. The SEM observations of the fractured surface revealed that the intermediate graded layer had the compositive mechanical properties in strength and toughness, due to the microstructure improvement and relaxation of residual stress concentration.

Due to its popularity and high crack sensitivity, 6061 aluminum alloy was selected as a test material for the newly developed double-sided arc welding (DSAW) process. The microstructure, crack sensitivity, and porosity of DSAW weldments were studied systematically. The percentage of fine equiaxed grains in the fully penetrated welds is greatly increased. Residual stresses are reduced. Porosity in the welds is reduced and individual pores are smaller. It was also found that the shape and size of porosity is related to solidification substructure. In particular, a weld metal zone with equiaxed grains tends to form small and dispersed porosity, whereas elongated porosity tends to occur in columnar grains.