M.D. Starostenkov
,
B. F. Demyanov
,
E.A. Kuklina and E. G. Sverdlova General Physics Department
,
Altai State Technical University
,
Lenin st 46
,
Barnaul
,
656099
,
Russia
金属学报(英文版)
Computer simulation of grain boundaries(GB) was carried out in Fe and ordered alloys NiAl and FeAl with B2 superlattice. In this work symmetrical tilt grain boundaries =5[100](012) and = 5[100](013) are studied. The atomic interaction has been described by Morse empirical central- force potentials.The atomic structure and energy of GB were investigated by means of construction of -surface using full atomic relaxation by method of molecular statics. It is shown that = 5 tilt GBs in Fe, Ni3Al and NiAl have several steady states. Comparison of our results with geometrical model of coincidence site lattice (CSL) was carried out. GBs in model CSL are unstable, the stabilization is achieved by additional displacement at some vector along the plane of defect.
关键词:
grain boundary
,
null
,
null
,
null
,
null
张卫玲
,
张健飞
高分子材料科学与工程
聚酯涤纶因其亲水性、抗静电性较差,起毛起球情况严重,不能成为理想的服用纤维,故须对其进行改性.文中从废水中筛选获得了解有效降解涤纶单体对苯二甲酸的菌株,菌种经鉴定显示其为革兰氏阴性杆菌B-F,对其进行驯化,探讨了最佳生长及产酶条件,获得了可用于涤纶纤维改性的生物酶.将获得的生物酶用于涤纶纤维改性处理,结果表明,处理后织物的亲水性、抗静电性得到一定程度的提高;抗起毛起球性能得到很好的改善;纤维表面产生一定量的活性基团;织物强力损失比化学改性要小得多.
关键词:
杆菌B-F
,
生物酶
,
对苯二甲酸
,
涤纶纤维
,
改性
X.H Luo
,
T.J. Su
,
C.G Fan
,
Y Y Liand CX Shi(Institute of Metal Research
,
Chinese Academy of Sciences
,
Shenyang 110015
,
China)X Chen and A.M Guo (Iron & Steel Research Institute
,
Wuhan Iron & Steel (Group) Company
,
Wuhan 430083
,
China)
金属学报(英文版)
1.25Cr-0.5Mo steels with different Ti-B or Al-B treatment were exposed in 18 MPa hydrogen atmosphere at 480℃ fo f 100, 500 and 1000 h respectively. Tensile and bend properties of steels before and after hydrogen changing were tested. The results show that the different mechanical properties of the steels with different B content have different responses to high temperature high pressure hydrogen charging processes.After hydrogen changing, more loss of ductility can be found in the steel not treated with B than those in the steels treated with B. Metallographic analyses indicated that decarburization occurred in all the steels. Furthermore, many methane bubbles were found by SEM analysis in the surface decarburization layer in the steel without B,while only a few bubbles, the number and size of which decreased with increasing B content, were found in steels with B treatment. In addition, hydrogen determination results manifested that after being exposed in hydrogen atmosphere the steel containing no B had higher hydrogen content than that of steels containing B. All this suggests that B treatment improved the HA resistance of 1.25Cgr-0.5Mo steel, and the more B the steel contained the more perceptible the effect.
关键词:
boron
,
null
,
null
,
null
Fatigue & Fracture of Engineering Materials & Structures
Fatigue crack growth behavior in welded joints subjected to elastic-plastic shock waves was investigated using three-point-bend specimens. The results indicate that the fatigue crack growth rate is reduced in the affected region of elastic or plastic waves. The travel of a plastic stress wave reaches 10 to 13 mm depth, but the hardness in this region is not increased although the lattice distortion is high. The crack path morphologies were observed, and reasons for a decrease in crack growth rate are presented.
关键词:
田中青
,
黄伟九
,
张春艳
,
余洪滔
材料导报
微波介质陶瓷是制作各种微波器件的关键材料.具有复合钙钛矿结构Ba(B'1/3 B"2/3)O3(B'=Mg,zn,Ni或Co;B"=Ta和Nb)型的微波介质陶瓷材料由于在很高的微波频率下具有极低的介电损耗而受到人们的重视.在总结前人研究成果并结合自己研究结果的基础上,从材料组成、结构、性能关系探讨了调节这类材料谐振频率温度系数的途径.
关键词:
微波介质陶瓷
,
复合钙钛矿
,
介电损耗
汤忖江
,
尚成嘉
,
关海龙
,
王学敏
材料研究学报
doi:10.11901/1005.3093.2015.696
采用TMCP工艺获得了5种不同贝氏体体积分数的铁素体/贝氏体(F/B)多相钢.通过纵向力学性能分析,并结合修正C-J分析方法研究了以F/B多相组织为特征的大变形管线钢的应变硬化行为,获得了F/B多相钢中贝氏体体积分数与应力比、屈强比的关系,并通过修正C-J分析对此现象的机理进行了合理的阐释.结果表明,大变形管线钢的弹性形变阶段主要对应修正C-J分析中的第Ⅰ阶段,塑性形变阶段包括修正C-J分析第Ⅱ和第Ⅲ阶段,屈服点(应变0.5％)附近阶段可跨越第Ⅰ和第Ⅱ阶段.F/B多相钢中各阶段的应变硬化能力存在显著差异,并且其应变硬化行为呈现出与贝氏体体积分数相关的特性.通过适宜的组织调控可以实现管线钢强度和塑性的最佳匹配.应力比Rt1.5/Rt05适宜用于表征管材屈服点附近的应变硬化能力,应力比Rt2/Rt1、Rt5/Rt1均适宜用于表征X70级管线钢塑性阶段应变硬化能力,Rt2/Rt1较适宜用于表征X80级管线钢塑性阶段应变硬化能力.
关键词:
金属材料
,
铁素体/贝氏体多相钢
,
大变形管线钢
,
应变硬化行为
,
修正C-J分析
,
贝氏体体积分数
,
应力比
,
屈强比
聂文金
,
尚成嘉
,
关海龙
,
张晓兵
,
陈少慧
金属学报
doi:10.3724/SP.J.1037.2011.00634
本文针对低C,高Mn和高Nb化学成分,采用轧后弛豫控制相变的组织调控技术得到5种不同铁素体/贝氏体(F/B)体积含量的双相组织钢.用改进的C-J分析方法分析了软相(铁素体)含量,研究了晶粒尺寸对加工硬化性能的影响,以及以铁素体和贝氏体为主的软硬相混合组织的塑性变形协调关系.并用电子背散射(EBSD)技术验证了双相组织在均匀塑性变形阶段的协调变形行为.结果表明,软硬相的合理比例有利于提高加工硬化程度(高Rt1.5/Rt0.5),降低屈强比,同时能保证较高的均匀变形能力,铁素体与贝氏体之间的协调变形是提高双相组织钢应力比和均匀伸长率的主要机制.
关键词:
铁素体/贝氏体双相钢
,
加工硬化行为
,
屈强比
,
均匀延伸
,
改进C-J分析方法
