Al—P中间合金对Al—Si合金的“绿色”变质

用 Al- 3P中间合金对 ZL1 0 9合金进行了变质生产试验 ,研究了其在生产中的工艺参数及加入工艺。对共晶成分的 Al- Si合金 ,其加入量按 W原料 × ( 0 .4%～ 0 .45 % ) + W回炉料 × 0 .1 %=WAl-3 P中间合金 进行计算称量 ,在 760～ 770℃变质即可取得良好的变质效果 ,生产出品质优良的活塞铸件。使用 Al- P中间合金变质剂加入方便 ,无渣无污染 ,可以提高合金的实收率、降低生产综合成本 ,适于工业化生产应用 ,是磷盐变质剂良好的替代品。     

TiC对新型Al-P中间合金变质效果的促进作用

本文研究了自制新型Al-P中间合金对共晶及过共晶Al-Si的变质作用。发现该Al-P中间合金对共晶及过共晶Al-Si合金都具有优良的变质效果。同时还发现，当铝合金熔体中存在TiC颗粒时，Al-P中间合金对两类Al-Si合金的变质效果会增强。当Al-24Si合金中TiC含量为0.03%时，初晶Si的平均尺寸由原来的47μm降为41μm，最大尺寸由原来的75μm降为55μm；加入Al-P中间合金和TiC颗粒后50分钟，就可以出现变质效果，时间再延长，变质效果也不会有更大的提高，当Al-12Si合金中TiC含量为0.03%时，初晶Si的平均尺寸幅度原来的50μm降为30μm,Al-P中间合金变质剂在铝合金活塞中有较好的应用。     

铝——硅共晶活塞合金的Na,P变质

本论文致力于KS1275活塞合金分别经Na,P变质后，在机械，物理性能以及铸造性能等方面的比较，同时基于铸造理论和实践结果，对影响P变质效果的一些重要因素进行分析，小结。     

涡流法判断铝硅合金活塞变质效果的方法

铝硅合金变质前后组织中共晶硅的形态发生明显变化,导致材料电导率改变,应用涡流传感器采集不同变质效果的试块或活塞的电信号,信信号的大小可判断铸件的变质效果。     

红梅-3号特种合金磷变质剂的研制与应用

为满足铝活塞产品质量的需要，继“红梅—1号多功能磷复合变质剂”和“红梅—2号磷酸盐块状变质剂”后，我们又新研制开发了多相长故、环保型“红梅—3号特种合金磷变质剂”。这是一种高技术合量的新型以—Si合金磷变质剂，无论在产品质量上、使用性能上还是变质效果可与国外生产的P——Cu棒变质剂媲美。     

氢含量对Al-P中间合金变质效果的影响

利用测氢仪等测试手段研究了 ZL1 0 9熔体中氢含量对 Al- P中间合金变质效果的影响。结果表明 ,在相同的铸造条件下 ,变质后合金中熔体氢含量越高 ,初晶 Si晶粒的平均晶粒尺寸和最大晶粒尺寸越大。保温时间过长合金熔体有吸氢倾向 ,初晶 Si尺寸有增大趋势。在精炼处理充分的条件下 ,Al- P中间合金的变质效果可保持 3 0小时不失效     

Al-P中间合金的变质特性及变质机理探讨

通过在众多活塞厂家应用表明：A1-P中间合金无污染、无反应渣，变质效果好且稳定；节约能源，降低铝耗，综合成本低，克服了当前变质的缺点，有着广阔的应用前景。本文还探讨了A1-P中间合金的变质机理。     

铝硅合金磷变质工艺的研究

本文在研究开发红梅-1号多功能磷复合变质剂、红梅-2号磷酸盐块状变质剂和红梅-3号特种合金磷变质剂的基础上，紧密联系活塞生产的实际，对Al-Si合金采用磷变质的各项工艺参数进行了研究探讨，重点对应用红梅-3号的工艺参数进行了研究探讨；同时，对磷变质相关的几个理论性的问题作了阐述，并对ZLl08和ZLl09合金成分的工艺配比提出了我们的建设性意见，希望对从事活塞生产已经和准备采用磷变质的厂家有一定指导意义。     

结晶硅中杂质Ca元素的分析方法改进

1 前言。众所周知，硅是活塞铝合金中一种重要组成成分，结晶硅是铝活塞铸造过程中一种重要原辅材料，而其中的Ca元素则是一种有害元素，杂质Ca是以硅化钙(Ca2Si、CaSi、CaSi2)、氮化钙等化合物形式出现的。当含杂质Ca较多时，将会使流动性变差，容易吸气和发生微观针孔或疏松，严重时产生偏析性硬脆化合物，     

Al—P中间合金变质剂在Al—Si活塞合金中的应用

在生产条件下比较了用Al-P中间合金与磷盐变质剂处理共晶和过共晶Al-Si合金的工艺特点、变质效果、力学性能和综合成本等，结果表明：使用Al-P中间合金操作方便，变质效果好、且稳定、力学性能也有不同程度的提高，而且该中间合金无渣、无污染，其使用可以实现生产过程的“零时间”变质处理，节约能源，提高生产效率，提高合金的实收率，降低产品的综合成本，有着良好的应用前景。     

Copper and phosphorus effect on residual embrittlement of irradiated model alloys and RPV steels after annealing

The dependence of the recovery of the transition temperature shift after annealing (475 °C, 100 h) on copper and phosphorus contents has been studied on irradiated reactor pressure vessel (RPV) materials. A set of model alloys with low nickel content, lower than 0.2 mass%, was used for the study. Copper and phosphorus contents were varied in a wide range: 0.005–0.99 and 0.002–0.039 mass%, respectively.     

An electrochemical investigation of melt-spun nanocrystalline Mg20Ni10−xCux (x = 0–4) electrode alloys

The nanocrystalline Mg₂Ni-type electrode alloys with nominal compositions of Mg₂₀Ni_10−xCu_x (x = 0, 1, 2, 3, 4) were synthesized by the melt spinning technique. The microstructures of the as-cast and spun alloys were characterized by XRD, SEM and HRTEM. The electrochemical hydrogen storage performances were tested by an automatic galvanostatic system. The results show that all the as-spun alloys hold typical nanocrystalline structure instead of an amorphous phase. The melt spinning does not modify the major phase Mg₂Ni, but it leads to the formation of crystal defects such as stacking faults, dislocations, sub-grain boundary and twin-grain boundary. The melt spinning significantly improves the electrochemical hydrogen storage capacity of the alloys, whereas it slightly impairs the electrochemical cycle stability of the alloys. The substitution of Cu for Ni significantly ameliorates the electrochemical hydrogen storage performances of the alloys, involving both the electrochemical hydrogen storage capacity and the electrochemical charging and discharging stability.     

Effect of Si content on H2 production using Al-Si alloy powders

The effect of Si content in Al-Si alloy powder with NaOH on H₂ production was investigated. The total amount of H₂ produced decreased as Si content increased, which is inconsistent with the results predicted by the chemical reaction. Si caused a delay in the rate of H₂ production. Energy dispersive spectrometry showed that a large amount of unreacted Si remained in the matrix, and the unreacted fraction increased as the Si content increased. As the evolution reaction of Al and Al-Si alloys is exothermic, the temperature of all the specimens increased. Si addition reduced the hydroxide removal rate, which decreased the average H₂ production rate. The initiation time for H₂ evolution depends on the elimination rate of the oxide film formed during production of the powder. On increasing the Si content, SiO₂ was formed, which is harder to eliminate than Al₂O₃; this delayed the initiation.     

Structure and hydrogen storage performances of La–Mg–Ni–Cu alloys prepared by melt spinning

The (Mg₂₄Ni₁₀Cu₂)_100-xLa_x(x = 0, 5, 10, 15, 20) alloys were prepared adopting the method of melt spinning technology. Adding La brings on the formation of secondary phases of La₂Mg₁₇ and LaMg₃, while it does not change the major phase of Mg₂Ni. Originally, there already have nanocrystals and amorphous structures in the experimental alloys, and the addition of La is more conducive to the formation of glass. With adding La in as-spun alloys, the gaseous hydrogen absorption capacity was significantly reduced, but it markedly improved their hydriding rates. Adding La and melt spinning considerably enhanced the dehydriding rate, the reason for which is the decrease of activation energy incurred by adding La and melt spinning. In addition, the discharge capacity of the alloys were able to reach a maximum value during La content varying, and it obviously increased with spinning rate rising.     

Al-Si合金与高温热管的传热性能试验

提出了一种基于太阳能碟式聚光器的Al-Si合金储能锅炉的构想,搭建了Al-Si合金与高温热管传热的实验平台。试验结果表明,Al-Si合金与高温热管之间的传热密度为54.4 kJ/m2。对Al-Si合金的传热温度分布进行模拟,以热流密度为54.4 kJ/m2,换热系数为200 W/(m2.K),空气温度25℃的对流边界条件时,模拟结果和试验测试结果比较吻合,为Al-Si合金储能锅炉设计提供了依据。     

Al-Si-Cu三元合金在太阳能高温相变蓄热装置中的数值分析

相变蓄热材料是太阳能热发电系统蓄热环节的关键。Al-Si-Cu三元合金作为相变蓄热材料具有性能稳定、衰减指数低、蓄热性能优良的特点。在实验的基础上,采用DSC、Hotdisk等方法对不同金属含量的Al-Si-Cu合金的热物性进行研究,同时对其封装材料进行了选择;基于不同形状蓄热单元,用Fluent软件进行模拟,最终选择了一个圆形相变蓄热单元和一个正六边形蓄热模块。结果表明：Al-Si-Cu三元合金相变蓄热材料集合了Al-Cu合金质量潜热大和Al-Si合金体积潜热大的优势;圆形结构蓄热单元换热性能最优;正六边形的模块能有效提高空间利用率,且更易于拼接,这对大型相变蓄热装置在工程中的应用具有重要意义。     

Irradiation embrittlement of model alloys and commercial steels: analysis of similitude behaviors

The deep understanding of the irradiation embrittlement of the pressure vessel of nuclear reactors is a key issue for the plant lifetime assessment and life extension through mitigation methods like annealing and much effort have been done in the last decades to tackle such complex issue. The reactor pressure vessel (RPV) material of nuclear power plants is exposed to neutron irradiation during its operation. Such exposure is generally inducing a degradation of the mechanical and physical properties of the materials, e.g. an increase of the ductile to brittle, DBT, transition temperature and a decrease of the upper shelf energy.The different response of materials to neutron irradiation, even many factors are also playing significant role, is mainly due, for a given exposure, to the chemical composition of the materials. In particular, for the RPV steel, elements like phosphorus, P, copper, Cu, and nickel, Ni, are playing a key role.A parametric study of the response to neutron irradiation of 32 different model alloys with parametric variation of elements (Ni from 0.004 to ∼2 wt%, P from 0.001 to 0.039 wt%, Cu from 0.005 to ∼1 wt%) has been recently completed within the frame of the European Network AMES and EC-JRC AMES Institutional project [1].Such study on model alloys reveals to be a fundamental tool to understand the individual role of each element and synergisms.To demonstrate the usefulness of the study to commercial RPV steels, an analysis of the results and the similitude of behavior between model alloys and available RPV commercial steels has been carried out and the results are presented in this paper.     

几种铝硅系耐火材料型壳的性能研究

熔模精密铸件的质量与型壳有密切关系,熔模精密铸造企业应该明确所使用的制壳材料和制壳工艺对型壳质量的影响。文章采用了公司已经试验较成熟且稳定的制壳工艺,选用硅溶胶为粘结剂,研究了几种铝硅系耐火材料型壳的性能,明确了各种型壳的适用性。     

Characterisation of an arc xenon lamp and its application to titanium nitride synthesis

Concentrated solar energy offers unknown possibilities on surface modification of materials. The characterisation of 7 kW arc xenon lamp is presented as a solar simulator. The lamp has a maximum net power density of about 220 Wcm⁻² with a spot of 8 mm diameter. With this equipment it is possible to treat steels and even melt of materials up to 2000K. Results are presented for the surface nitriding of Ti alloys performed in a nitrogen reaction chamber at atmospheric pressure. The good quality of the TiN coating is demonstrated by scanning electron microscopy, X-ray diffraction and Vickers hardeness (hardness about 1000 HV). Treating times could be as short as 30 s because the growth rate is about 4 μm/min. This rate is higher than many other nitriding processes. These results are a previous experimental work to direct nitriding of Ti alloys in real solar concentrating equipment.     

A numerical study of thermocapillary flow in a rectangular cavity during laser melting

The surface tension gradient driven flow that occurs during laser melting has been studied. The vorticity-streamfunction form of the Navier-Stokes equations and the energy equation has been solved by the ‘Alternative Direction Implicit’ method. It has been shown that the inertia forces in the melt strongly influence the flow pattern in the melt. The convection in the melt modifies the isotherms in the melt at high surface tension Reynolds number and high Prandtl number. The buoyancy driven flow has been shown to be negligible compared to the surface tension gradient driven flow in laser melting.