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On-line ultrasonic monitoring of polymer injection molding and aluminum die casting are presented. The flow front of molten polymer and aluminum inside the mold has been probed by a multiple-channel acquisition system with a time resolution up to 1 ms. This information may be used to control the plunger movement. The gap development, due to the shrinkage of the part in the mold, and the part solidification are also monitored for the understanding of the cooling process. As expected, it is observed that thicker sections take longer times to solidify. For injection molding, the relation between the gap formation time and packing pressure has been investigated. Since the temperature of molten aluminum is around 700°C, ultrasonic waveguides are inserted into the die for the monitoring.

Dispersion of nanoclay in Epikote 828 resin is conducted by closed mixing of the liquid composition, mechanical mixing combined with ultrasonic vibration to form masterbatch; meanwhile, nanoclay dispersion in bitumen is processed by melted bitumen mixing. XRD techniques were used to determine the basal d-spacing of nanoclay. The dispersion was performed in Brabender mixer at temperature 40oC, speed 50 rpm, an Epikot/I30E=100/80 masterbatch provided the best dispersion with d001=33.818 Å. After mechanical mixing, an Epikote 828 composition with 4% I30E was sonicated for 5, 10, and 20 minutes. The value d001=41.65 Å achieved after 10 minutes of sonication was deemed optimal. Dispersion of 4% I30E in melted bitumen at 120, 130, 140, 150, and 160oC after 2h reached d001=49.5916 Å for the sample processed at 120oC. At high temperatures, penetration and delamination of bitumen were better than those of Epikote 828 despite the lower molecular weight of Epikote.

The results of corrosion survey for stainless steel tanks used in water storage at various areas are presented. More severe corrosion is observed for the area with higher airborne salinity. Damages are revealed at both outer and inner surfaces for tanks made of Type 304 and 201 steels exposed in coastal conditions. Corrosion products examined by visual inspection and SEM-EDX technique showed relatively distinctive characteristics for the outer and inner tank surfaces which are attributed to different corrosion mechanisms initiated by corrosive chloride accumulated on steel surfaces. Airborne salinity is considered the main source causing corrosion of Type 304 and 201 stainless steel tanks.