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1.
采用透射电镜(TEM)研究了Ni47Ti44Ta9合金中马氏体和β-Ta相的形貌及精细组织。结果表明,马氏体主要呈细板条状和群团状两种形貌,其亚结构为孪晶;β-Ta相粒子呈椭球状分布于TiNi基体中,其内部存在大量位错和孪晶。  相似文献   

2.
郑玉峰  王中 《金属学报》1999,35(4):365-370
利用透射电镜和高分辨电镜系统地研究了Ti36Ni49Hf15合金的显微组织与相结构、热致马氏体形貌、亚结构、马氏体变体间的组织结构和界面结构结果表明,固溶处理Ti(36)Ni(49)Hf(15)合金的室温组织由马氏体基体和呈球状与多边形状的(TixHf(1-x))2Ni第二相粒子组成.马氏体相为单斜B19’结构,点阵常数为:α=0.2454nm,b=04087nm,c=0.4791nm;)β=99.32°.Ti(36)Ni(49)Hf(15)合金的热形成马氏体变体间构成典型的自协作组态观察到的有矛头状、嵌镶块状和楔状三种形态马氏体变体其亚结构为(001)复合李晶.矛头状和嵌镶块状马氏体变体之间互成(011)Ⅰ型、<011>Ⅱ型孪晶关系,在这些变体内部还存在与其呈(111)Ⅰ型孪晶关系的楔状小变体.(011)Ⅰ型孪品界面比较平直、共格性好、界面两侧原子相对(011)面呈镜面对称;<011>Ⅱ型孪晶界面呈现缓慢弯曲的特征;(111)Ⅰ型孪晶界面呈波浪形结构  相似文献   

3.
Ni9钢微观结构的TEM研究   总被引:1,自引:0,他引:1  
李光来  孟祥敏  张弗天  吴玉琨 《金属学报》1996,32(11):1121-1129
利用TEM研究了Ni9钢中马氏体与奥氏体的微观结构,结果表明,多数回火奥氏体不是严格地按K-S或N-W关系析出,而是在这两种取向附近变化;在同一马氏体束内,奥氏体可按上述近似关系的不同变化析出;回火奥氏体主药第马氏体晶界析出,呈板条状,惯习面为(335)//(341),奥氏体向马氏体转变时易形成马氏体孪晶,这是孪晶在随后的回火过程中消失。  相似文献   

4.
赵连城  蔡伟 《金属学报》1997,33(1):90-98
用透射电镜、高分辨电镜、不同温度下的拉伸试验以及电阻率-温度曲线测试研究了Ni-Ti-Nb合金形变诱发马氏体相变及其可逆性,分析了形变诱发马氏体的稳定性和可逆性与其变体界面结构之间的关系。结果表明,Ni-Ti-Nb合金在Ms-Ms^σ温度区间加应力时发生应力诱发马氏体相变,而在Ms^σ以上温度加应力时,发生应变诱发马氏体相变。形变对Ni-Ti-Nb合金的应力诱发马氏体界面结构有明显影响,随着拉伸变  相似文献   

5.
Zr-Nb合金氧化膜物相及结构分析   总被引:1,自引:0,他引:1  
研究了Zr—2.5Nb和Zr—1.0Nb—0.5Fe合金的氧化膜结构。XRD分析表明,Zr—2.5Nb合金氧化膜主要由单斜型(ZrO2)M组成,还存在(ZrO2)x变态。对Zr—1.0Nb—0.5Fe合金的氧化膜进行了TEM分析,得到了清晰的晶粒及孪晶亚结构。  相似文献   

6.
Fe—Mn—Si—Cr—Ni记忆合金形变组织的TEM研究   总被引:3,自引:0,他引:3  
戎利建  平德海 《金属学报》1995,31(9):A399-A404
本文利用X射线衍射及透射电镜分析研究了元素Cr,Ni对Fe-Mn-Si合金c/α值及形变诱发ε马氏体显微组织的影响,结果表明,添加Cr,Ni后,合金的c/α值由1.620提高至1.656,其结果使合金中的fcc形变孪晶易形成;通过在孪晶内形成ε马氏体,可避免不同取向马氏体之间的穿的越过程。骨利于合金的记忆效应。  相似文献   

7.
刘雅晶  李玉清 《金属学报》1999,35(10):1036-1042
对低Al,高Ti,Nb(合金A)和高Al、低Ti,Nb(合金B)两种成分特征的Fe-Ni-Cr-Co-Nb-Ti-Al合金宏观和微观铸态组织的观察分析表明,合金A凝固速度较快,柱状晶区较大;两者枝晶间及铸态晶界上都分布着较多块(厚片)状富含Nb和Ti的MC和Laves相多晶体;合金B柱状晶区晶界Laves相较多;合金A晶界MC和Laves相附近析 体状γ′和η相及胞状η相;合金BKγ′的尺寸仅约为  相似文献   

8.
Fe-Mn-Si-Cr-Ni记忆合金形变组织的TEM研究   总被引:3,自引:0,他引:3  
本文利用X射线衍射及透射电镜分析研究了元素Cr,Ni对Fe-Mn-Si合金c/a值及形变诱发ε马氏体显微组织的影响.结果表明:添加Cr,Ni后.合金的c/a值由1.620提高至1.656,其结果使合金中的fcc形变孪晶易形成:通过在孪晶内形成ε马氏体,可避免不同取向马氏体之间的穿越过程,从而有利于合金的记忆效应.  相似文献   

9.
表面机械研磨诱导AISI 304不锈钢表层纳米化Ⅱ.晶粒细化机理   总被引:24,自引:2,他引:24  
张洪旺  刘刚  黑祖昆  吕坚  卢柯 《金属学报》2003,39(4):347-350
采用表面机械研磨处理(SMAT)在AISI 304不锈钢上制备出纳米结构表层,用透射电镜(TEM)研究组织演变过程.晶粒细化机理可归纳如下:位错在{111}面上滑移并相互交割形成网格结构;单系孪晶形成并逐渐过渡到多系孪晶;多系孪晶相互交割使晶粒尺寸不断减小,并在孪晶交叉处形成了马氏体相;孪晶系增多与孪晶重复交割强度加大使得细化晶粒的尺寸进一步减小;最终在大应变量、高应变速率和多方向重复载荷的作用下,形成等轴状、取向呈随机分布的马氏体相纳米晶组织.  相似文献   

10.
高锰无磁钢的组织形态   总被引:1,自引:0,他引:1  
本文利用光学金相、X射线衍射及透射电镜研究,发现高锰无磁钢具有两种不同形态的板条组织和ε马氏体的扭折形态。固溶淬火形成的断续状短板条及形变诱发形成的细长板条都是由ε马氏体和fcc孪晶所组成,讨论了形成机理。晶体学分析表明,fcc孪晶界两侧的ε马氏体成扭析形态,是因为孪晶界两侧的基体位向不同所致,扭折部分为hcp孪晶。  相似文献   

11.
In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.  相似文献   

12.
After nearly two years' tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry (SRIF), located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.  相似文献   

13.
The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).  相似文献   

14.
The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.  相似文献   

15.
Tang Dynasty 《中国铸造》2014,(4):I0002-I0003
<正>Bronze mirrors were used by the Chinese people before the introduction of the glass mirror.Only after it was replaced by the glass mirror did the bronze mirror gradually retreat from people's lives.Different styles of bronze mirrors were made in different historical periods,particularly in the Warring States Period,the Han and Tang Dynasties,which were the three peaks of the development of bronze mirror arts in ancient China.The casting techniques were exquisite.The surface of the bronze mirror was smooth and bright enough to reflect one's image,and there were scarcely any casting defects on the mirror surface.On the back of the bronze mirror,there were rich depictions of Arts and Humanities,and the ornamentations were also  相似文献   

16.
《中国铸造》2014,(5):464-466
The 9th China International Diecasting Congress & Exhibition was held on July 22-24, 2014 at Shanghai New International Expc Centre. This exhibition was the most successful over the years, with over 6890 visitors and 155 exhibitors, and the exhibition area increased by 30% from 9,500 square meters in 2012 to 12340 square meters. Die casting enterprises from a total of 24 countries and regions, including China mainland, Chinese Taiwan and Hong Kong, South Korea, Japan, Germany, India, Thailand, Malaysia, the United States, Russia, Australia, Iran, Ukraine, Brazil, Colombia, Singapore, Austria, Canada, Croatia, France, Turkey, United Kingdom, Vietnam, attended the congress and exhibition.  相似文献   

17.
正The Fluid Control Engineering Institute of Kunming University of Science and Technology was set up in 1996.The researches of institute concentrate on electro-hydraulic(pneumatic)servo/proportional control and hydromechatronics.The Institute is committed to research and development of electro-hydraulic control of high-end technical equipment in ferrous metallurgy refining produc-  相似文献   

18.
19.
Antimony induced crystallization of PVD (physics vapor deposition) amorphous silicon can be observed on sapphire substrates. Very large crystalline regions up to several tens of micrometers can be formed. The Si diffraction patterns of the area of crystallization can be observed with TEM (transmission electron microscopy). Only a few and much smaller crystals of the order of 1μm were formed when the antimony layer was deposited by MBE (molecular beam epitaxy) compared with a layer formed by thermal evaporation. The use of high vacuum is essential in order to observe any Sb induced crystallization at all. In addition it is necessary to take measures to limit the evaporation of the antimony.  相似文献   

20.
Fatigue damage increases with the applied loading cycles in a cumulative manner and the material deteriorates with the corrosion time. A cumulative fatigue damage rule under the alternative of corrosion or cyclic loading was proposed. The specimens of aluminum alloy LY12-CZ soaked in corrosive liquid for different times were tested under the constant amplitude cyclic loading to obtain S-N curves. The test was carried out to verify the proposed cumulative fatigue damage rule under the different combinations among corrosion time, loading level, and the cycle numbers. It was shown that the predicted residual fatigue lives showed a good agreement with the experimental results and the proposed rule was simple and can be easily adopted.  相似文献   

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