检索结果-南通市图书馆

ordering transformation OF γ TO γ_1 IN TiAl+Nb SYSTEM

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 1995年第1期9卷 6+1-6页

作者：王金国陈国良叶恒强北京科技大学新金属材料国家重点实验室中国科学院金属研究所固体原子象实验室

A series of TiAl+Nb alloys with various Nb contents has been employed to explore phase relationship and the evolution of microstructure.A new ordered γ derivative (γ1) has been observed in the alloy containing 20 at% *** additional diffraction spots added to the diffraction pattern of L10 (TiAl) structure have been found in the alloy containing Nb up to 11 at% in terms of further *** transformation from L10 (TiAl) structure to the further ordering phase,γ1,is a continuous ordering process with the substitution of Nb atoms for Ti atoms in alloys with over-stoichiometric Al content of *** possible transformtion characterzation has been discussed.

关键词： intermetallics Ti-Al-Nb system superstructure ordering transformation

ON THE ordering transformationS IN Ti_3AL-Nb ALLOY

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 1991年第3期4卷 204-208页

作者： LI Dong ZHOU Jing CHANG Xin GUAN Shaoxuan Institute of Metal Research,Academia Sinica,Shenyang,China

Study was made of the behaviour of ordering transformation in Ti_3AI-Nb alloy,including the ordering at high temperatures,the transformation of high temperature β-phase during cooling,and the decomposition of metastable β-phase during *** results show that the ordered primary α_2 and high temperature β in alloy form at 1060℃.The transformation of high temperature β-phase proceed by β→α_2+ω type during cooling,and the decomposition of metastable β and ω type proceeded by(β+ω)_(metustabte)→(α_2+β)_(stable)during aging at 700℃.

关键词： Ti_3Al-Nb alloy ordering transformation α_2-phase β-phase ω-phase

Effect of Cd on matrix structure ordering and aging precipitation evolution in a Mg-Gd-Cd solid-solution alloy

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2023年第8期11卷 2833-2852页

作者： Lin-Lin Liu Wei Sun Cuixiu Liu Pengyang Sun Institute of Microstructure and Property of Advanced Materials Beijing University of TechnologyBeijing 100124China

The formation and evolution of Gd-rich precipitates companying with the matrix structure ordering in a Mg_(97)Gd_(2)Cd_(1)(at.%)solid-solution alloy aged at 200℃have been systemically investigated using high-angle annular dark-field scanning transmission electron microscopy(HAADF-STEM).The results show that Gd-rich precipitation dynamics during the aging treatment are noticeably affected by a continuous ordering transformation in the *** ordering transformation process involving mainly re-distribution of Cd atoms was revealed to occur in the following way:random super-saturated solid solution(S.S.S.S.)→B19-type ordered domains→D019-type ordered *** Gd(Cd)-rich precipitates,G.P.Ⅰ zone,G.P.Ⅱ zone,β′andβ_(1)phases,have been observed to be formed in sequence to coexist with the various ordered *** on the HAADF-STEM characterization on the aging microstructures at different aging stages,it can be concluded that the Cd-addition and related matrix structure ordering can play significant roles in modifying the early-stage *** structure,altering the morphology ofβ′precipitates and promoting the forming ability of theβ_(1)precipitate.

关键词： Mg-Gd-Cd alloy ordering transformation Aging microstructure Precipitation evolution HAADF-STEM

INVESTIGATION OF PHASE SEPARATION OF THE Fe-Ni-Co-Al-Cu-Ti PERMANENT MAGNET ALLOY

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2000年第2期13卷 816-820页

作者： W.G. Chu W.D. Fei and D.Z. Yang (School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China)

Microstructure formed in the Fe-Ni-Co-Al-Cu-Ti permanent magnetic alloy with different treatments was studied by means of TEM observation, XRD method and SAXS technology. The results indicated that spinodal decomposition and orderiing transformation coexisted in the alloy and spinodal decomposition was completed in a short time. The ratio of component of spinodal and ordered microstructure was dependent on the cooling rate. The variation of gyration radius RG of the rod-like precipitates could be accounted for by the different growth modes of the precipitates related to strain energy and interface energy.

关键词： Fe-Ni-Co-Al-Cu-Ti permanent magnetic alloy spinodal decomposition ordering transformation microstructure