材料期刊网，材料期刊，材料类期刊，材料期刊投稿

INFLUENCE OF PRECIPITATES ON THE TWO WAY SHAPE MEMORY EFFECT

M Liu , XM Zhang , M.Z. Liu , X.M. Mengand Y Y Li(Institute of Metal Research , Chinese Academy of Sciences , Shenyang 110015 , China)(Metal Material Department , Sichuan Union University , Chengdu 610065 , China)

金属学报(英文版)

In this paper by means of TEM and HREM, we found that the presence of r-phase plays the most important role in enabling two way shape memory effect (TWME) to be obtained by the stabilization of stress induced martensite variants (SSIM). This idea is different from the traditional suggestion that strain fields developed by dislocation produced TWME. With prolonged isothermal ageing time, the bainitic tronsforma-tion product α1 precipitated, the amount of γ-phase increased, while the martensite was retained and became less ondered. These factors all reduced TWME. During age-ing, the stacking faults in bainitic product α1 disappeared, which indicated that the bainitic product α1 is a sub-equilibrium phase. The interfaces of α-plates also lost straightness step by step, some plates twisted, bronched and overlapped. Its formation is irreversible in tnorphology and reduces the quantities of martensite. Although the precipitation of r may stabilize some martensite or oppose its growth,α may hinder nucleation of martensite. Thus, it was considered that α-plates were the worst de- stroyed element. These suggestions agreed well with our performance test results in that the transformation temperntures and the amount of TWME changed in the same way with prolonged ageing, firstly increasing and then decreasing after reaching an optimal maximum value.

关键词: precipitate , null , null , null

XM-505盐水介质缓蚀剂的研制

郭良生 , 黄霓裳 , 石小燕 , 邱富荣

材料保护 doi:10.3969/j.issn.1001-1560.1999.02.019

XM-505盐水介质缓蚀剂是由硫脲、醇胺磷酸酯、磷酸二氢锌和乌洛托品组成的.它对抑制钢铁在盐水中腐蚀尤其有效,浓度为2 000 mg/L时,缓蚀率高达98.0%.这种缓蚀剂不仅高效,而且剂量小,成本低,原材料无毒.

关键词: 缓蚀剂 , 盐水 , 钢铁

各种因素对XM-101磷系缓蚀剂缓蚀效果的影响

郭良生 , 黄霓裳 , 余兴增 , 石小燕 , 邱富荣

腐蚀与防护 doi:10.3969/j.issn.1005-748X.2000.12.002

采用失重法、表面观察法和极化曲线法研究了缓蚀剂浓度、溶液的pH值、Cl-、Ca2+和温度等诸因素对XM-101磷系缓蚀剂缓蚀效果的影响.结果发现:当XM-101浓度为75mg/L,溶液的pH值为7.15时,XM-101对自来水中碳钢的缓蚀率接近100%.

关键词: 缓蚀剂 , 自来水 , 碳钢 , 腐蚀 , 抑制

TiFe_xM_y氢化物形成焓的数学模型与计算预报

周自强 , 冯锋 , 张金龙 , 平信义

材料研究学报

研究了TiFe_xM_y 合金氢化物(M 代表Mn,Ni,Co,Zr,Nb,V,Cr 和Al,x≥0.5,y≤0.3)分解自由能变化△G 与形成热△H 和元素原子参数间的关系。结果表明;氢化物分解时的△G可以用合金组成元素的原子尺寸因素、元素的平均电负性差和平均外层电子数的半经验方程式来表示,并由此可推出氢化物分解热△H,计算预报值与实际值相符,相差在5kJ(mol H_2)~(-1)以内。比较三参数对△H 的贡献大小表明,TiFe_xM_y 合金的△H 主要受电负性差或电子因素控制。

关键词: 计算预报 , TiFe_xM_y alloy , hydride , enthalpy of formation , mathematical model