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Structural and Microstructural Function of Protium

氕的结构和微观结构功能

基本信息

批准号：
10148101
负责人：
AOKI Kiyoshi
金额：
$ 81.28万
依托单位：
Kitami Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research on Priority Areas (A)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 2001
项目状态：
已结题

项目摘要

The pressure dependence of structural changes of C15 Laves phase TbFe_2 heated in a hydrogen atmosphere was investigated using PDSC, XRD, DSC and a hydrogen analyzer. Hydrogen absorption in the crystalline state, hydrogen-induced amorphization (HIA), precipitation of TbH_2 and decomposition of the remaining amorphous alloy into ヲチ-Fe and TbH_2 occurred exothermally with increasing temperature above 0.5 MPa H_2, independent of the heating rate. HIA and precipitation of TbH_2 occurred simultaneously in 0.2 MPa H_2 (O.33 K/s) and in 0.1 MPa H_2 (0.17 K/s). On the contrary, hydrogen absorbed crystalline c-TbFe_2H_<3.5> decomposed directly into ヲチ-Fe and TbH_2 in O.1 MPa H_2 (O.33 K/s). That is, no amorphous phase was formed at the lower hydrogen pressure and at a high heating rate. The reason why HIA occurs above the critical hydrogen pressure and below the critical heating rate was discussed on the basis of the hydrogen content absorbed in the crystalline state of The Fe _2. 2) Formation … More of hydrogen-induced superabundant vacancies has been studied in Cr-H, Mn-H, Ni-H and Nb-H alloys and its energetics and structure dependence has been elucidated. 3) The relationship between hydrogen pressure and temperature (P-Tcurve) in the HDDR treatment of the Sm_2Fe_<l7> compound was investigated. The P-T curve suggested that the HDDR condition of the Sm_2Fe_<l7> compound was more sensitive to temperature than that of the Nd_2Fe_<l4>B compound. In addition, for clarifying the mechanism of anisotropic inducement during the HDDR process in the Nd-Fe-B compound, the crystal orientation relationship between the parent Nd_2Fe_<l4>B phase and the disproportionated mixture was investigated. It can be concluded that retaining the crystallographic orientation relationship such as <111>ヲチ-Fe and <111>NdH_2// <001>Nd_2Fe_<l4>B, (110)ヲチ-Fe and (110)NdH_2//(lOO)Nd_2Fe_<l4>B during HDDR treatment is important for the inducement of anisotropy. 4) It has been found that the tensile specimen of ultra-fine grained Ti-6Al-4V alloy elongates until the diameter of the tip of the broken specimen narrowed to the size of a single crystal. The implant (dental part) was produced using the ultra-fine grained material without crack on the surface by the superplastic forming process. These materials may be applicable as biomaterials in medical industries. Less

采用PDSC、XRD、DSC和氢分析仪研究了C15 Laves相TbFe_2在氢气气氛中加热时结构变化的压力依赖性。在0.5 MPa H_2以上，随着温度的升高，晶态吸氢、氢致非晶化（HIA）、TbH_2的析出以及剩余非晶态合金分解为-Fe和TbH_2的过程均发生放热，与升温速率无关。在0.2 MPa H_2 （0.33 K/s）和0.1 MPa H_2 （0.17 K/s）条件下，HIA和TbH_2的降水同时发生。而在0.1 MPa H_2 （0.33 K/s）条件下，c-TbFe_2H_<3.5>的吸氢结晶则直接分解为-Fe和TbH_2。即在较低的氢压力和较高的加热速率下，未形成非晶态相。根据Fe _2结晶态吸收的氢含量，讨论了在临界氢压以上和临界升温速率以下发生HIA的原因。2)研究了Cr-H、Mn-H、Ni-H和Nb-H合金中氢致超丰空位的形成，并阐明了其能量学和结构依赖关系。3)研究了Sm_2Fe_< 17 >化合物HDDR处理过程中氢气压力与温度的关系（p - t曲线）。P-T曲线表明Sm_2Fe_<l7>化合物的HDDR条件比Nd_2Fe_<l4 b> B化合物对温度更敏感。此外，为了阐明Nd-Fe-B化合物在HDDR过程中各向异性诱导的机理，研究了母相Nd_2Fe_< 14 >B与歧化混合物之间的晶体取向关系。结果表明，在HDDR处理过程中保持<111> -Fe和<111>NdH_2// <001>Nd_2Fe_<l4>B, (110) -Fe和（110）NdH_2//(lOO)Nd_2Fe_<l4>B的晶体取向关系是诱导各向异性的重要因素。4)发现超细晶Ti-6Al-4V合金拉伸试样伸长，直至断裂试样尖端直径变窄至单晶大小。采用超塑性成形工艺制备了表面无裂纹的超细晶材料。这些材料可作为生物材料应用于医疗行业。少