생체용 Ti-Hf 이원계합금의 열처리 과정에 따른 미세구조와 기계적 특성의 변화

Abstract

The biological Cp-Ti has excellent biocompatibility, it widely used dental implants and artificial joint. But it is not strong enough for some dental applications. Since Hf belongs to the same group as Ti in the periodic table of elements, it likely possesses excellent biocompatibility. In the present study, Ti-Hf (10 ,20, 30 and 40 wt%) prepared by vacuum arc melting method. Heat treatment was carried by furnace cooling and quenching into ice water, respectively. All specimens investigated mechanical properties and microstructure. As the increase of Hf contents, microstructure translated lamellar structure to needle-like structure. Especially, water quenching specimen rather than furnace cooling specimen showed finest structure. The results of XRD showed that peaks of α-phase structure appears over all region. EDX results indicated that composite of alloy became homogenization. Micro Vickers hardness test showed that hardness and tensile strength increased with increasing Hf content. Water quenching specimen than furnace cooling specimen showed more higher hardness and tensile strength value. These result are as follow : 1.Microstructure clearly observed that lamellar structure translated to needle-like structure with increased Hf contents. Especially, microstructure of water quenched Ti-Hf specimens more fine than furnace cooling specimen. 2. As a result of XRD, α-phase peak was detected for all samples. 3.From the results of Micro Vickers hardness test, Ti- 40Hf alloy showed significantly increasing of hardness and tensile strength than others in the case of both water quenched and furnace cooling sample. 4.Hardness and tensile strength value of water quenched sample had higher than those of furnace cooling sample. 5.The results of EDX indicated that Hf content appears in needle-like structure.