Porous and dense TiNi alloys were successfully fabricated by powder metallurgy(P/M) method, and to further improve their surface biocompatibility, surface modification techniques including grind using silicon-carbide(...Porous and dense TiNi alloys were successfully fabricated by powder metallurgy(P/M) method, and to further improve their surface biocompatibility, surface modification techniques including grind using silicon-carbide(SiC) paper, acid etching and alkali treatment were employed to produce either irregularly rough surface or micro-porous surface roughness. X-ray diffractometry(XRD), scanning electron microscopy(SEM) and energy dispersive X-ray spectroscopy(EDX) attached to SEM were used to characterize surface structure and the Ca-P coatings. Effects of the above surface treatments on the surface morphology, apatite forming ability were systematically investigated. Results indicate that all the above surface treatments increase the apatite forming ability of TiNi alloys in varying degrees when soaked in simulated body fluid(SBF). More apatite coatings formed on TiNi samples sintered at 1050℃ and 1100℃ due to their high porosity and pure TiNi phase that is beneficial to heterogeneous nucleation. Furthermore, more uniform apatite was fabricated on the sample sintered from the mixture of Ni and Ti powders.展开更多
The magnetic domain structures of the 100 oriented Fe 81 Ga 19 polycrystalline alloys with rapid quenching(RQ) and post-annealing(PA) thermal treatments are investigated by using magnetic force microscopy(MFM).The sur...The magnetic domain structures of the 100 oriented Fe 81 Ga 19 polycrystalline alloys with rapid quenching(RQ) and post-annealing(PA) thermal treatments are investigated by using magnetic force microscopy(MFM).The surfaces of the RQ alloy rods take on the dendritic domains after undergoing a standard mechanical polishing.While after PA processing,the distinct domain structures are observed at different temperatures.The wide stripe-like domain patterns appear in the surface of those PA rods at 550°C while the ramous domains remain at 400°C annealing.X-ray diffraction patterns indicate that a thin iron layer is formed on the surface of the specimens annealed at higher temperature.The soft magnetic iron layer,actually acting as a shield for the stray fields emerging from the internal magnetic structures underneath,brings about the presentation of the wide internal domains.展开更多
基金Project(51274247) supported by the National Natural Science Foundation of ChinaProject(2014zzts177) support by the Fundamental Research Funds for the Central Universities,China
文摘Porous and dense TiNi alloys were successfully fabricated by powder metallurgy(P/M) method, and to further improve their surface biocompatibility, surface modification techniques including grind using silicon-carbide(SiC) paper, acid etching and alkali treatment were employed to produce either irregularly rough surface or micro-porous surface roughness. X-ray diffractometry(XRD), scanning electron microscopy(SEM) and energy dispersive X-ray spectroscopy(EDX) attached to SEM were used to characterize surface structure and the Ca-P coatings. Effects of the above surface treatments on the surface morphology, apatite forming ability were systematically investigated. Results indicate that all the above surface treatments increase the apatite forming ability of TiNi alloys in varying degrees when soaked in simulated body fluid(SBF). More apatite coatings formed on TiNi samples sintered at 1050℃ and 1100℃ due to their high porosity and pure TiNi phase that is beneficial to heterogeneous nucleation. Furthermore, more uniform apatite was fabricated on the sample sintered from the mixture of Ni and Ti powders.
基金supported partially by Hunan Provincial Science and Technology Department of China (Grant No. 2012WK3032)
文摘The magnetic domain structures of the 100 oriented Fe 81 Ga 19 polycrystalline alloys with rapid quenching(RQ) and post-annealing(PA) thermal treatments are investigated by using magnetic force microscopy(MFM).The surfaces of the RQ alloy rods take on the dendritic domains after undergoing a standard mechanical polishing.While after PA processing,the distinct domain structures are observed at different temperatures.The wide stripe-like domain patterns appear in the surface of those PA rods at 550°C while the ramous domains remain at 400°C annealing.X-ray diffraction patterns indicate that a thin iron layer is formed on the surface of the specimens annealed at higher temperature.The soft magnetic iron layer,actually acting as a shield for the stray fields emerging from the internal magnetic structures underneath,brings about the presentation of the wide internal domains.
