http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Kaveh Hajizadeh (검색결과 2 건)
- 무료
- 기관 내 무료
- 유료
-
Kaveh Hajizadeh,Beitallah Eghbali 대한금속·재료학회 2014 METALS AND MATERIALS International Vol.20 No.2
The present work investigates the microstructural and mechanical properties of commercial purity titaniumafter processing by a two-step severe plastic deformation procedure entailing warm equal channel angularpressing (ECAP) followed by cold rolling at liquid nitrogen temperature (LNT). The effect of subsequent coldrolling at room temperature is also investigated for comparison. After 10 passes of ECAP, an ultrafine-grainedstructure with average grain size of 213 nm was achieved. Subsequent cold rolling at LNT led to further refinementand decreased the grain size to 114 nm. Under these conditions, the material displayed high tensilestrength of 995 MPa and high elongation to failure of 23%. These promising mechanical properties were interpretedin terms of characteristics of the microstructure: grain refinement, increased dislocation density, and ahigh fraction of high angle grain boundaries.
-
Yalda Chehrehsaz,Kaveh Hajizadeh,Afra Hadjizadeh,Lida Moradi,Sara Mahshid 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.6
Despite many advantages of titanium, such as proper mechanical properties, biocompatibility and corrosion resistance, ithas two main weaknesses; low tensile strength compared to other metallic biomaterials, and inadequate osseointegrationowing to its bioinert spontaneous surface oxide layer. Grain refinement using Equal Channel Angular Pressing (ECAP) hasbeen preferred as a desirable method to enhance low tensile strength. In addition, osseointegration could be improved byelectrochemical oxidation (anodization), resulting in titania nanotubes formation on titanium surface. The latter has beenextensively studied on commercially pure titanium (CP-Ti), and the formed nanotubes have been well characterized. However,a thorough observation on anodic nanotubes of ECAP-processed coarse-grained pure titanium (CG-Ti) is missing. In thisresearch, we aimed to investigate the surface characteristics and cytotoxicity of anodic TiO2nanotubes on ECAP-processedCP-Ti substrate compared to that of CG-Ti. The results generally showed superior use of nanotubes anodized on ECAP-edCP-Ti substrates over that of coarse-grained ones. We acquired ultrafine-grained titanium (UFG-Ti) by ECAP, and synthesizedanodic nanotube arrays on both UFG-Ti and CG-Ti at different times and voltages. We compared the resulted nanotubes’morphologies, physicochemical and biological properties, in which cell culture on anodic TiO2nanotubes of ECAP-edCP-Ti has been performed for the first time by this research. FESEM results showed relatively lower diameter and longernanotubes for UFG-Ti samples rather than CG-Ti ones. Nanotubes of both substrates were amorphous, and CG-Ti nanotubeswere more hydrophilic than UFG-Ti nanotubes. Enhanced cell viability and proliferation were achieved on ECAP-ed CP-Tianodic TiO2nanotubes.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
