YC. Liu
,
G.C. Yang
,
YL. Lu and Z.G. Zhu (State Key Lab. of Solidification Processing
,
Northwestern Polytechnic University
,
Xi'an 710072
,
China Laboratory of Internal Friction and Defects in Solids
,
Chinese Academy of Science
,
Hefei 230031
,
China )
金属学报(英文版)
The effects of cerium modification and extrusion on the resultant damping behavior and mechanical properties of the as-sprayed high silicon alloy ZA27 were investigated in an thort to develop a new functional material possessing high damping capacity and good mechanical properties. The damping capacity, as well as the rslative dynamic modulus, was tneasured at frequencies of 1 and 4 Hertz over the 30 to 200℃runge. At below 80℃ the as-sprayed materials appear to be approximately Asquency independent. Above 80℃, the,naterials becotne temperature sensitive, exhibiting the highest damping for the lowest hequency. The extruded, as-sprayed high silicon alloy ZA27 modified by cerium has the highest damping capacity and elongation values among them. The micro8tructure of the as-sprayed high silicon alloy ZA27 modified by 0. 5 wt% cerium was made up of fine lamellar eutectoid, porositg, a light dot-like phase and a polygonal silicon-rich phase. Finally, the opemtive damping tnechanisms were discussed in light of the data obtained hem characterization of microstructure and damping capacity. The high damping capacity was attributed primarily to phase interface thermoelastic damping between the lamellar phases with various substrvctures,except for the grain refinement.
关键词:
spray deposition
,
null
,
null
,
null
徐嘉鹏
,
李家鸣
,
高俊章
,
陈东
功能材料
就航天工程用耐蚀高强卫星动力弹簧合金3YC42进行了产品材料质量工程研究.确证了计算成份按固溶强化、形变强化和库尔纳阔夫状态强化的优化组合是从产品质量要求出发的最佳的成份,组织结构和性能质量工程控制,展示了我国设计与研制高科技领域所需材料及其质量控制的水平和能力.
关键词:
弹性合金
,
耐蚀合金
,
质量工程控制
吴旻
功能材料
3YC7热电偶保护管在测量电渣沸腾炉温度时熔断,采用宏观检验、化学成分分析、金相检验等方法,对保护管进行了分析,发现保护管断口处的热影响区较短,结合对保护管在使用时所测的电渣沸腾炉的情况的调查,认为,保护管的熔断是因炉内电弧放电造成局部温度过高所导致.
关键词:
3YC7
,
热电偶保护管
,
熔断
刘淑坤
,
彭乔
,
王海潮
腐蚀与防护
研究开发了一种羧酸盐类低聚型气相缓蚀剂YC-1,采用了经典的失重法和电化学方法对其气相防锈能力进行了评价.结果表明,其分子内各个活性单元具有强烈的分子内协同效应,使其在海洋性大气下对黄铜具有优良的缓蚀作用,对钢铁也有一定的保护作用.电化学极化曲线研究表明,它对金属的阳极过程有明显的抑制作用.
关键词:
低聚物
,
气相缓蚀剂
,
海洋性大气
,
分子内协同效应
,
低毒
,
通用
张玉碧
,
李永友
,
王东哲
,
高小丽
,
李济林
,
安身景
,
张华礼
,
尹强
材料保护
为了探讨酸性油气田腐蚀环境中油气管材料的腐蚀性能，自制了3YC51镍基耐蚀合金，分别采用高温高压釜和同步热分析仪对其在高温高压湿H：S环境下的耐蚀性能和1300℃恒温空气中的高温氧化行为进行了研究。结果表明：3YC51合金在试验条件下具有优良的耐均匀腐蚀和应力腐蚀性能；3YC51能满足酸性油气环境对金属材料的使用要求。合金氧化分2个阶段，初始氧化温度为1047℃，在1153℃和1287℃分别出现氧化极值点，氧化增重呈抛物线形状，具有较高的初始氧化温度和较好的抗高温氧化性能。
关键词:
3YC51镍基耐蚀合金
,
应力腐蚀开裂
,
高温氧化行为
,
湿H2S
,
酸性油气田
Physical Review B
The magnetic, transport, and magnetotransport properties of Mn3+xSn1-xC (0 <= x <= 0.4) and Mn3ZnySn1-yC (0 <= y <= 0.9) compounds are investigated systematically. For Mn3+xSn1-xC, a sharp rise in temperature dependence of resistivity is observed for x <= 0.1, accompanied by a magnetic phase transition from a paramagnetic state to a complicated spin arrangement composed of antiferromagnetic and ferromagnetic sublattices. A different behavior appears in the resistivity of Mn3.2Sn0.8C, which decreases monotonically with decreasing temperature. A partial Zn substitution for Sn in Mn3SnC leads to dramatic changes of magnetic and transport properties. As the temperature decreases, a magnetic transition from the ferromagnetic (or ferrimagnetic) to antiferromagnetic state occurs at about 170 and 142 K for Mn3Zn0.4Sn0.6C and Mn3Zn0.5Sn0.5C compounds, respectively, which strongly affects their transport properties. A significant magnetoresistance as large as 34% is observed for Mn3Zn0.5Sn0.5C at 95 K, in accordance with a field-induced metamagnetic transition. The origin of the magnetoresistance effect is discussed in terms of the reconstruction of the Fermi surface.
关键词:
giant magnetoresistance;transition;manganese;mn3gac;multilayers;exchange;alloys;mn3snc;mn3znc
范华
,
王天剑
机械工程材料
doi:10.11973/jxgccl201603024
利用热力学计算软件 Thermo-Calc 计算出不同温度下3325YC1钢中 M23 C6和 M2 B 析出相的含量,以及铬、钨、钼元素含量对这两种相析出温度和析出量的影响；在此基础上通过降低铬、钨、硼含量对钢的成分进行调整,并对成分调整前后钢的高温拉伸、疲劳和持久性能进行了对比试验.结果表明：铬是 M23 C6和 M2 B 相的主要形成元素,增加铬含量对这两种相的析出量没有影响；钨是 M2 B 的主要形成元素,随着钨含量增加,M2 B 的析出量增加,但析出温度没有变化；硼含量增加能明显提高 Cr2 B 和 M2 B 相的析出量,但不影响它们的析出温度；钢的成分调整后基本不会影响它的高温瞬时拉伸性能和疲劳性能,其在620℃、10万 h 的 Larson-Miller 外推持久断裂强度仍高于100 MPa.
关键词:
汽轮机
,
高温叶片
,
析出相
,
热力学计算
Journal of Alloys and Compounds
The structure, phase transformation and magnetic properties of SmyFe100-1.5y C-0.5y (y=10, 12, 14, 16, 18, 20) alloys prepared by mechanical alloying (MA) have been studied systematically. The Sm2Fe17Cx (Sm2Fe14C) phase tends to form when y is increased (decreased). For the same composition, the Sm2Fe17Cx phase is formed more easily when the annealing temperature T-n is lower. No Sm2Fe14C phase is observed in the Sm20Fe70C10 alloy. In other alloys, annealed between 650 degrees C and 950 degrees C, the Sm2Fe14C and Sm2Fe17Cx phases coexist under a certain condition. Re-milling and re-annealing proved to be suitable for improving the magnetic properties of the MA alloys. After annealing at 800 degrees C for 35 min, re-milling for I h and then re-annealing at 600 degrees C for 35 min, the value (BH)(max), = 10.6 MGOe has been achieved for the MA Sm14Fe79C7 alloy. After annealing at 800 degrees C for 35 min, the MA Sm20Fe70C10 alloy was re-milled for 1 h and then re-annealed at 550 degrees C for 2 h, resulting in the value of H-i(e) =7.96 kOe. (C) 1999 Elsevier Science S.A. All rights reserved.
关键词:
samarium iron carbides;magnetic properties;mechanical alloying;permanent-magnets;sm;fe;r2fe14c;nd
