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1.
Ni-Cr-3%Al-0.2%Ce合金0.3mm细丝经500-600℃时效处理,用透射和扫描电镜观察组织形貌,用化学定量提取法和测定微区成分的方法确定相Ni、Cr、Al的含量,用程控图像仪测定富Cr(α)相析出颗粒大小和分布,查明了γ相沿基体9100)面共格析出并细小颗粒状,在γ相周围析出的过饱和富Cr(α)相弥散分布在合金基体中,据此认为该合金是由γ相和富Cr(α)相复合析出强化合金基体的。  相似文献   

2.
通过热力学计算,选择Ni_2O_3粉末作原材料,采用反应挤压铸造方法实现了Al与Ni2O3直接压铸反应合成Al3Ni-Al2O3-Al原位复合材料。研究了压铸工艺参数和预制块中纯Al粉的含量对反应合成复合材料过程的影响,并对反应机理做了较深入的分析。结果表明,Ni2O3与Al的反应是为高放热反应,反应是爆发式的,通过调整预制块中Al粉的体积分数控制了反应的剧烈程度,并能获得不同组成和基体含量的复合材料。对反应机理的分析表明,在Al足量的情况下,Ni2O3与Al反应合成复合材料分为两个过程,一是反应过程,即Ni2O3+Al→Al2O3+[Ni];二是凝固过程,即反应后多余的Al与反应生成的[Ni]在随后冷却中的凝固过程,最终形成Al3Ni+α-Al2O3+Al复合材料。  相似文献   

3.
反应自生Al3Ni—Al2O3—Al复合材料   总被引:4,自引:0,他引:4  
通过热力学计算,选择Ni2O3粉末作原材料,采用反庆挤压铸造方法实现了Al与Ni2O3直接压铸反应合成Al3Ni-Al2O3-Al原位复合材料,研究了压铸工艺数和预制块中纯Al粉的含量对反应合成复合材料过程扣影响,并对反应机理做了较深入的分析。结果表明,Ni2O3与Al的反应是为高放热反应,反应是爆发式的,通过调整预制块中Al粉的体积分数控制了反应的剧烈程度,并能获得不必基体含量的复合材料,对反应  相似文献   

4.
采用真空钎焊工艺,将WC-Co硬质合金粉和NiCrBSi(AWSBNi-2)合金粉钎焊到45#钢表面,得到(WC-Co/NiCrBSi)钎焊涂层。不同钎焊工艺下,涂层及涂层/基体的拉伸强度分别达100—140MPa和300-360MPa。初步分析了钎焊涂层结合机制。涂层的磨料磨损性能远高于同配比的火焰堆焊涂层及Co-Cr-W堆焊层  相似文献   

5.
WC/Ni60A等离子喷涂层的相结构分析   总被引:7,自引:0,他引:7  
利用X射线衍射,SEM,EDAX,TEM及选区电子衍射等手段研究了WC/Ni60A等离子喷涂层的显微组织及其相结构。结果表明:涂层组织呈片层状,在Ni基合金片层中的镍基固溶体上析出了大量高度弥散分布的M7C3,M23C6及Ni3B;由于等离子喷涂温度较高,WC大部分熔化并与Ni包覆层相溶,发生高温分解,在Ni包WC片层中形成了弥散程度很高的M6C及α-W2C颗粒相。  相似文献   

6.
本文对Al_2O_3(Ti,W)C和SiCw-Al_2O_3(Ti,W)C的力学性能进行了分析对比,研究了热压工艺、SiC晶须含量、晶须分散效果和晶须/基体的复合情况等对Al_2O_3(Ti,W)C复相陶瓷力学性能的影响。从热膨胀系数失配角度分析和微观结构的观察证实,SiC晶须及(Ti,W)C固溶体对改善Al_2O_3陶瓷力学性能的效果是显著的,SiC_w-Al_2O_3.(Ti,W)C陶瓷材料的增韧机制主要是裂纹偏转和裂纹桥接。  相似文献   

7.
本文对Al_2O_3(Ti,W)C和SiCw-Al_2O_3(Ti,W)C的力学性能进行了分析对比,研究了热压工艺、SiC晶须含量、晶须分散效果和晶须/基体的复合情况等对Al_2O_3(Ti,W)C复相陶瓷力学性能的影响。从热膨胀系数失配角度分析和微观结构的观察证实,SiC晶须及(Ti,W)C固溶体对改善Al_2O_3陶瓷力学性能的效果是显著的,SiC_w-Al_2O_3.(Ti,W)C陶瓷材料的增韧机制主要是裂纹偏转和裂纹桥接。  相似文献   

8.
储双杰  吴人洁 《材料工程》1998,(6):17-19,22
利用挤压铸造法制造Cf/Al-4.5Cu复合材料,并在透射电子显微镜上了分析了基界面的微观结构特征。结果表明:Cf/Al-4.5Cu复合材料界面存在CuAl2与Al4C3析出相,Al4C3呈细棒状,而CuAl2相表现为柱状、块状片状;由于碳纤维与Al-4.5Cu基体间热膨胀系数不匹配产生的热应力铸造过程中Al-4.5Cu基体产生塑性有,使得在界面附近的基体和CuAl2相中产生大量位错缺陷。Af/A  相似文献   

9.
万立骏  陈宝清 《真空》1991,(5):42-46
利用SEM、TEM以及x射线衍射,研究了磁控溅射Al膜的退火对膜组织 结构转变的影响。Al膜被磁控溅射在Ni基体上,所得镀膜分别经 100℃、200℃、 300℃、400℃、500℃、550℃和 600℃真空退火。结果表明, 100℃开始 Al膜再结晶; 400℃开始有Al-Ni金属间化合物相生成,随温度升高,金属间化合物相的形成顺序为 Al3Ni—Al3Ni2-Ni3Al AlNi。薄膜的组织也由开始的细颗粒状组织转变为多边形 晶粒组织。  相似文献   

10.
研究了Ni3Al金属间化合物及溅射CoCrAlY涂层在900~950℃空气中,表面存在(Na,K)2SO4盐膜时的热腐蚀行为,结果表明,Ni3Al遭受严重的热腐蚀,溅射CoCrAlY涂层可以通过在表面迅速形成保护性Al,Cr氧化膜而显著改善Ni3Al的耐热腐蚀性能。  相似文献   

11.
In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.  相似文献   

12.
Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……  相似文献   

13.
14.
A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.  相似文献   

15.
On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……  相似文献   

16.
Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.  相似文献   

17.
In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M2(B,C), (W,Mo)2(B,C), M3(B,C), M23(B,C)6 type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm2. The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K1 mill housing of bar mill.  相似文献   

18.
The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...  相似文献   

19.
正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from  相似文献   

20.
正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.  相似文献   

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