含Be多元合金非晶形成能力的替代效应研究

利用晶胞平移和分子动力学模拟建立了Zr4lTil3.8Be22.5Ni17.5Cu5．2晶态和非晶合金的原子结构模型，利用递归方法研究了Zr4lTi13.8Be22．5Ni17．5Cu5．2晶态及非晶态合金中元素的替代效应．Be与B、Al、Si状态密度形状相似表明Be与B、Al、Si具有相似的性质，可以用Al、B、Si代替Be；非晶态相对于晶态的结构能差表明，用Al、B、Si代替Be后均使合金的非晶形成能力下降，只是Al、B下降的幅度较小；用Al、B替代Be，再用其它过渡金属替代Cu、Ni或zr、Ti可使非晶形成能力达到含Be合金的水平．     

锆基大块非晶合金及其晶化合金在0.5mol/L H2SO4中的腐蚀行为研究

根据合金的DSC曲线制定了Zr60Al15Ni25、Zr52.5Al10Ni10Cu15Be12.5和Zr65Al10Ni10Cu15等锆基大块非晶合金的等温退火工艺,获得了与非晶态合金具有相同成分的晶化合金。通过研究非晶态合金和晶化合金在0.5mol/L H2SO4中的极化曲线,结合扫描电镜(SEM)和能量散射X射线谱(EDS)分析,发现,在0.5mol/LH2SO4中非晶态合金和晶化合金都具有非常优异的耐腐蚀性能,但非晶合金的耐腐蚀性能要比晶化合金稍好。这主要是因为晶态合金的结构中不存在晶界、位错等缺陷,同时非晶态合金中的组元具有很高的活性,使合金更快地进入钝态。     

大块非晶合金Zr55Cu30Al10Ni5的电子结构特征及电击穿行为

测定了大块非晶合金Zr55Cu30Al10Ni5晶化前后的费米能级和各元素的电子结合能,研究了非品合金的电子结构特征和电击穿行为．测试并讨论了非晶材料场发射能力和耐电压强度的关系．结果表明,对于Zr基合金,非品态比品态合金具有更大的功函数．比较了Zr55Cu30Al10Ni5合金非晶态与晶态的耐电压强度数值,发现非晶态合金的耐电压强度数值比较分散,品化合金的耐电压强度相对比较集中．耐电压强度平均值表明,Zr基合金非晶态具有更好的耐电压能力．     

大块非晶合金Zr55Cu30Al10Ni5及其晶态合金的氧化行为研究

采用DSC、TGA、XRD等实验手段研究了大块非晶合金Zr55Cu30Al10Ni5各种状态的氧化行为。结果表明非晶态样品的氧化速率最快,稳定晶化态样品的氧化速率最慢,这说明晶态相Zr2Cu具有良好的抗氧化性。非晶态和晶态样品的氧化动力学均遵循线性规律。     

Zr基大块非晶合金成分的等电子浓度和等原子尺寸判据

制备了6种合金Zr65.5Al5.6Ni6.5Cu22.4,Zr65.3Al6.5Ni8.2Cu20,Zr65Al7.5Ni10Cu7.5,Zr64.8Al8.3Ni11.4Cu5.5,Zr64.5Al9.2Ni13.2Cu13.1和Zr63.8Al11.4Ni17.2Cu7.6,共晶成分位于合金Zr64.5Al9.2Ni13.2Cu13.1和合金Zr63.8Al11.4Ni17.2Cu7.6的成分之间，这6种合金均显示了非晶相的形成和较宽的过冷液相区范围△Tx值，以及较大的约化玻璃转变温度Trg值，除合金Zr63.8Al11.4Ni17.2Cu7.6的△Tx值为87K外，其余5种成分合金的△Tx值均在97K以上，最宽的达105K，表明这6种合金是一个具有大玻璃形成能力和高热稳定性的非晶合金系列，合金Zr63.8Al11.4Ni17.2Cu7.6是6种合金中玻璃表成能力和热稳定性最高的，其Tg，Tx和Trg值最高，Inoue非晶合金Zr65Al7.5Ni10Cu17.5并不是最佳非晶成分，提出以等电子浓度和等原子尺寸规律作为设计大块非晶合金成分的判据。     

大块非晶合金的性能、制备及应用

综述了大块非晶合金的性能、制备方法及应用，对比了吸铸法制备的棒状Zr41.2Ti13.8Cu12.5Ni10Be22.5,Zr57Cu20Al10Ni8Ti5,Zr52.5Ti5Cu17.9Ni14.6Al10(原子分数)大块非晶样品的过冷温度区间宽度(△Tx)，给出了3种大块非晶合金系列的热稳定性参数Tg、Tx及△Tx，提出了大块非晶合金领域存在的问题及发展方向．     

Zr-Al-Ni-Cu大块非晶合金的电化学腐蚀行为研究

用电化学方法研究了 6种不同成分的大块非晶合金、与非晶成分相对应的两种晶态合金和纯Zr在 0 .1mol/LNa2 SO4 溶液中的腐蚀行为 ,结果表明 ,6种非晶样品中 ,有 4种具有高耐蚀性能 ,其中 ,成分为Zr65Al7.5Ni10 Cu17.5的样品具有最低的icorr值 1.38× 10 - 2 μA·cm- 2 。两种具有相同成分的非晶与晶态合金相比 ,晶态合金具有更低的icorr值。在 9种实验样品中纯Zr具有最低的icorr值 7.10× 10 - 3 μA·cm- 2 。     

Zr基块体非晶合金的成分设计及其性能研究

根据二元共晶混合法设计Zr-Cu-Ni-Al非晶合金成分,利用铜模吸铸法制备Zr-Cu-Ni-Al合金棒材.采用XRD、DSC、SEM及准静态压缩实验研究了所设计合金的非晶形成能力和力学性能.结果表明:所设计的Zr-Cu-Ni-Al合金均为非晶态结构,其过冷液相区(ΔTx)均超过65 K,有较好的非晶形成能力,其中Zr55.7 Cu22.4 Ni7.2 Al14.7合金的ΔTx最宽,达到82 K;合金的塑性变形能力由低到高依次为:Zr57 Cu18.67 Ni8 Al16.33、Zr56.36 Cu20.53-Ni7.6 Al15.51、Zr54.4 Cu26.13 Ni6.4 Al13.07和Zr55.7 Cu22.4 Ni7.2 Al14.7,其中Zr55.7 Cu22.4 Ni7.2 Al14.7的塑性达到5.5％,抗压强度达到1885 MPa,其他三种合金的塑性均不足2％.剪切带的增殖和交互作用与非晶合金的塑性和强度密切相关.合金试样断口中均有熔滴存在,这表明在合金变形过程中,断裂处的合金组织发生了粘性流动,并伴有脉纹产生.合金在塑性变形中均发生了锯齿流变,锯齿流变与自由体积的变化密切相关.     

微量元素对Cu-Zr-Al系非晶合金性能的影响

通过对直径为3mm成分为Cu50Zr43Al7、(Cu50Zr43Al7)100-xYx(x=2,5)、(Cu50Zr43Al7)100-xAgx(x=6,7)的非晶合金进行X射线衍射(XRD)和差分扫描量热(DSC)的测试分析,研究了微量元素Ag、Y对Cu50Zr43Al7块状非晶的玻璃形成能力和热稳定性的影响。结果表明,添加适当微量的Ag和Y元素,提高了合金的热稳定性和玻璃形成能力,但Ag元素比Y元素的作用要更加显著。利用动电位极化法对各非晶合金在3.5%NaCl溶液中的电化学测试表明,各非晶合金的耐腐蚀性均远远好于相应的晶态合金。添加了微量的Ag、Y元素提高了Cu50Zr43Al7非晶合金的耐蚀性能,Cu43Zr43Al7Ag7非晶合金的腐蚀电流密度比Cu50Zr43Al7的降低了1～2个数量级。     

Ti-Zr-Be-Cu-Co块体非晶合金在NaCl溶液中的冲刷腐蚀行为

为评价Ti基块体非晶合金的耐蚀性,以期今后在工业生产中的应用,采用失重法研究了Ti35Zr30Be2 4Cu7.5Co3.5块体非晶合金及其对应晶体成分在质量分数6%Na Cl溶液中0.2、0.4、0.6 m/s流速下的冲刷腐蚀行为.利用X射线分析(XRD)、扫描电镜(SEM)研究了Ti35Zr30Be2 4Cu7.5Co3.5块体非晶合金及其对应晶体成分的相结构、微观腐蚀形貌,并利用电化学极化试验测试2种合金冲刷腐蚀后的耐蚀性.结果表明:随着流速的增加,2种合金的腐蚀速度均升高,其中非晶合金出现最大腐蚀速度峰值的时间由无冲刷状态的32 h缩短到流速为0.6 m/s下的10 h,Ti35Zr30Be2 4Cu7.5Co3.5块体非晶合金腐蚀速度较对应晶体成分小;Ti35Zr30Be2 4Cu7.5Co3.5块体非晶合金较对应晶体成分在质量分数6%NaCl溶液中具有更好的耐蚀性.     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

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.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

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

Flow calorimeter for enthalpy increment measurements on condensed gases

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.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

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.……     

Optimum-Simulation von Ernteprozessen

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.     

A study of centrifugal cast high boron high speed steel

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.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

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 ...     

Brainstorming for ISO Strategy 2016-2020

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     

CNAS Passes APLAC's PTP Review

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.