This article presents the successful consolidation of the mixed Co and Diamond powders for a drilling segment by the combined application of magnetic pulsed compaction (MPC) and subsequent sintering, and their properties were analyzed. Homogeneous hardness (Hv 220) and density (97%) of sintered bulks fabricated by MPC were obtained by the new technique, where higher pressure has been employed for short period of time than that of general process. A fine microstructure and homogeneous hardness in the consolidated bulk were observed without cracks. Relatively higher drilling speed of 9.61 cm/min and life time of 6.55 m were found to the MPCed specimens, whereas the value of the specimens fabricated by general process was 11.71 cm/min and 7.96 m, respectively. A substantial improvement of mechanical properties of segment was achieved through this study.

In this study, the colloidal stability and sedimentation behavior of crystalline particles (300nm) in various organic solvents have been investigated by means of a backscattered light flux profile (Turbiscan). The backscattered light flux profiles revealed that the nanoparticles were readily sedimented in water, methyl alcohol, and ethyl alcohol due to a flocculation-induced particle growth, while a particle coalescence and a sedimentation of the nanoparticles were hardly observed in isopropyl alcohol. The migration velocities of the particle were measured as around 6.15/min, 12.53 m/min, 6.51m/min, and 0.18m/min for water, methyl alcohol, ethyl alcohol, and isopropyl alcohol, respectively, showing a remarkably slow migration of the particles in isopropyl alcohol

Aluminum hydroxides were synthesized by a simple electrolytic reaction of aluminum plates. The aluminum hydroxide, boehmite (AlO(OH)), was predominantly formed in the application of electrical potential at and above 30V, while the mixture of bayerite () and boehmite (AlO(OH)) phases were formed below 20V. The boehmite has a clear fibrous structure controlled on nanometer scale. On the contrary, the bayerite consists of the typical hourglass or semi-hourglass shaped coarse crystals as a result of aggregation of various crystals stacked together. The specific surface area of the boehmite nanofiber was markedly high, approaching at about .