• Proceedings of the Materials Research Society of Korea Conference
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• 2000.11a
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• pp.60-60
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• 2000

• Journal of the Korean Society for Heat Treatment
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• v.37 no.6
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• pp.297-302
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• 2024

The aim of the present study is to verify the microstructural and mechanical properties of Ta-Zr dissimilar metals welded using TIG welding. Due to the significant differences in thermo-mechanical properties, microstructures were observed across the weld zone. The HAZ exhibited grain coarsening, while the Zr-side HAZ showed significant Ta diffusion. The fusion zone (FZ) displayed cellular and equiaxed structures. Hardness tests indicated a higher hardness in the FZ due to solid solution strengthening and spinodal decomposition. Tensile tests revealed fracture in the Ta-side HAZ, caused by shrinkage defects and brittle Ta oxides. Fracture surface analysis showed brittle patterns, highlighting the need for defect control in dissimilar Ta-Zr welds.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.452-455
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• 2003

[ $ZrO_2$ ] dielectric layers were grown on the p-type Si (100) substrate by metalorganic molecular beam epitaxy(MOMBE). Zrconium t-butoxide, $Zr(O{\cdot}t-C_4H_9)_4$ was used as a Zr precursor and Argon gas was used as a carrier gas. The thickness of the layers was measured by scanning electron microscopy (SEM) and the properties of the $ZrO_2$ layers were evaluated by X-ray diffraction, high frequency capacitance-voltage measurement. and HF C-V measurements have shown that $ZrO_2$ layer grown by MOMBE has a high dielectric constant (k=18-19). The growth rate is affected by various process variables such as substrate temperature, bubbler temperature, Ar, and $O_2$ gas flows.

• Molecular & Cellular Toxicology
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• v.2 no.2
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• pp.97-105
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• 2006

Several features of the implant surface, such as roughness, topography, and composition play a relevant role in implant integration with bone. This study was conducted in order to determine the effects of ceramic-coatings on Ti surfaces on the biological responses of a human osteoblast-like cell line (MG63). MG63 cells were cultured on Zr (Zrconium-coated surface), Nb (Niobium-coated surface), and control (Uncoated Titanium) Ti. The morphology of these cells was assessed by SEM. The cDNAs prepared from the total RNAs of the MG63 were hybridized into a human cDNA microarray (1,152 elements). The appearances of the surfaces observed by SEM were different on each of the three dental substrate types. MG63 cells cultured on Zr, Nb and control exhibited cell-matrix interactions. In the expression of several genes were up-, and down-regulated on the different surfaces. The attachment and expression of key osteogenic regulatory genes were enhanced by the surface morphology of the dental materials used.