급속소결방법인 고주파유도가열 소결법과 펄스전류활성 소결법을 이용하여 습식 볼밀링으로 혼합한 WC-8wt.%Ni분말에 60MPa의 압력과 고주파유도가열장치의 경우 전체 용량 (15kw)의 90%에 해당하는 고주파출력을, 펄스전류활성 소결장치의 경우 2800A의 펄스전류를 가하여 치밀한 소결체를 2분이내의 짧은 시간에 제조하였다. WC 초기입자크기가 증가함에 따라 제조된 소결체의 입자크기와 평균자유행로는 증가하였다. 또한 WC 결정립 크기가 증가함에 따라

In this study the nanostructured ceramics have been fabricated by the combined application of magnetic pulsed compaction (MPC) and subsequent spark plasma sintering (SPS), and their density and hardness properties were investigated. The prepared by the combined processes showed an increase by in density, approaching the value close to the true density, and an enhancement by in hardness, compared to those fabricated by MPC or static compaction method followed by sintering treatment.

To evaluate parameters influencing on the dust removal of the High Temperature Filter(HTF) system, a computer simulation of fluid dynamics inside the system had been performed. The results showed that the optimum pulse jet periods were 50ms and 90ms for the 1000mm and 1500mm long filter elements respectively. Dust removal effect was very excellent under the pulse jet pressure of 3 bar. But the distance between the pulse jet nozzle and the venturi of a filter element had no meaningful effect on the performance with the variation from 5mm to 10mm. Compared to the dispersion mode of pulse jet, the collective mode of pulse jet flow was preferable in maintaining the pressure inside the system stable.

Nano Fe-6.5wt%Si powders have been synthesized by mechano-chemical process (MCP) for an application of soft magnetic core. Owing to hard and brittle characteristics of Fe-6.5Si nano powders having large surface area, it is very difficult to reach high density more than 70% of theoretical density (~7.4 g/) by cold compaction. To overcome such problem a magnetic pulsed compaction (MPC), which is one of dynamic compaction techniques, was applied. The green density was achieved about 78% (~5.8 g/) by MPC at room temperature.

The aim of this study is to assess a looseness in a bolt being utilized for connecting components of a structural elements with the help of an Nd:YAG pulsed laser scanning system. Ultrasonic wave propagation imaging (UWPI) of a waveform generated using laser light and recorded by AE sensor was first found. Filtering operation was performed to remove an incident wave. The energy in the reflected wave was further assessed to arrive at a result which indicates structural defect has appeared, i.e., bolt loosening.