薄壁铸铁件湿型铸造涂料的实验与应用

本文介绍铸铁湿型铸造中的型腔表面使用的喷涂涂料,该涂料可有效的防止粘砂、掉砂、冲砂等铸造缺陷。铸件表面质量明显提高。     

Hydrogen,bifilms and mechanical properties of Al castings

Recent research has suggested that H dissolved in an Al melt could diffuse into double oxide films (bifilms), increasing their size and forming oxide related hydrogen containing porosity, which was found to decrease the Weibull moduli of the tensile properties of castings. In this work, the Weibull moduli of the tensile properties of two Al castings, both expected to contain oxide films of approximately the same amount and age, were compared. The results showed that, when the H content of the castings was reduced to ～50%, from 0·18 to 0·08 cm³/100 g Al, there was an increase in the Weibull moduli of the ultimate tensile strength (UTS) and the % elongation by ～400% and 200% respectively. The increased Weibull modulus was thought to be brought about by holding the moulds under vacuum and thus reducing H pick-up by the metal, from the solvent and the resin in the sand moulds.     

Review of porous anodic aluminium oxide (AAO) applications for sensors,MEMS and biomedical devices

Anodising of aluminium is one of the simplest metal surface finishing processes, and results in a porous anodic aluminium oxide (AAO) which is integral with the parent metal. Pore size, interpore spacing and thickness of the porous oxide film can be controlled by careful selection of the anodising electrolyte (type and concentration), and the operating parameters (voltage, temperature, time) employed. A self-ordered nanoporous AAO can be obtained without the need for expensive or complex processes required for traditional materials employed in microelectronics and MEMS applications (e.g. photolithography in the production of porous silicon). Planar and curved AAO surfaces can be manufactured. The simple and low-cost process for the production of AAO has enabled this material to gain inroads in the manufacture of various sensors and MEMS devices. This review paper discusses the anodising process and the resulting AAO structures tailored for MEMS, sensors, biomedical and nanotechnology fabrication.     

SO2 abatement,energy conservation,and productivity at copper cliff

Inco pioneered the use of tonnage oxygen in nonferrous metallurgy when it commissioned the first industrial oxygen flash smelting process for the treatment of copper concentrates in the early 1950s. This was followed by other applications of oxygen such as the enrichment of reverberatory furnace and Peirce-Smith converter blasts; oxy-fuel smelting in reverb furnaces; and, very recently, flash conversion of chalcocite to copper. Inco is currently implementing a sulfur dioxide abatement project designed to reduce SO₂ emissions from the smelter by 60 percent (to 265 kt) in 1994. At that time, oxygen consumption at the smelter will reach about 1.7 t O₂/t Cu+Ni. Oxygen smelting and converting technology will lead toa substantial decrease in the use of fossil fuels and to the generation afhigh-strength SO₂ off-gases suitable for cost-effective fixation in a new acid plant.     

玻璃熔炉烟气脱硫、除尘、脱硝技术开发

简介彩电玻壳生产线锥炉、屏炉烟气脱硫、除尘、脱硝设备技术开发.投产应用表明,整套技术可在玻壳行业及其它类似行业推广应用.     

涂料技术的发展、配方及种类

本文包含了涂料的发展。它显示了涂料制造厂商是怎样开发新配方以满足新环境条件和规则所带来的日益增长的要求。本文讨论了常用的涂料，介绍了涂料领域的技术、服务的基本理解和认识。     

Fe-Al、Ti-Al和Ni-Al系金属间化合物多孔材料的研究进展

总结Fe-Al、Ti-Al、Ni-Al 3大系金属间化合物的物相结构和基本特性,论述Fe-Al、Ti-Al和Ni-Al 3大类金属间化合物多孔材料的制备方法、孔结构表征以及耐腐蚀性能,并指出孔结构参数的可控性研究、复合材料的制备和焊接性能的提高是金属间化合物多孔材料未来的研究重点.     

节能、降耗、减排是硅热法炼镁发展的生命力

为使硅热法炼镁达到节能、降耗、减排的目的,介绍了白云石、硅铁的质与量,煅白中CaO的水化活性度、炉料的物理性质、球团真空还原时供热与传热速度、镁蒸气的生成与扩散速度的能量与质量的动态平衡条件以及提升装备水平和设备大型化等方面的技术要求。     

Validation of a systematic approach to modeling spray quenching of aluminum alloy extrusions, composites, and continuous castings

Optimal cooling of aluminum alloys following the high- temperature extrusion process suppresses precipitation of intermetallic compounds and results in a part capable of possessing maximum strength and hardness after the subsequent age- hardening process. Rapid quenching suppresses precipitation but can lead to large spatial temperature gradients in complex- shaped parts, causing distortion, cracking, high residual stress, and/or nonuniform mechanical properties. Conversely, slow cooling significantly reduces or eliminates these undesirable conditions but allows considerable precipitation, resulting in low strength, soft spots, and/or low corrosion resistance. This study presents a systematic method of locating and operating multiple spray nozzles for any shaped extrusion such that uniform, rapid cooling and superior mechanical and metallurgical properties are achieved. A spray nozzle data base was compiled by measuring the distribution of spray hydrodynamic parameters (volumetric spray flux, mean drop diameter, and mean drop velocity) throughout the spray field of various industrial nozzles. Spray heat transfer correlations, which link the local spray hydrodynamic parameters to the heat transfer rate in each of the boiling regimes experienced by the surface, defined the spatially nonuniform boundary conditions in a numerical model of the quenching process that also accounted for interference between adjacent spray fields. New correlations, offering increased accuracy and less computational time, were formulated for the high- temperature boiling regimes which have a critical influence on final mechanical properties. The quench factor technique related predicted thermal history to metallurgical transformations occurring within the extrusion to predict hardness distribution. The validity of this unique approach was demonstrated by comparing model predictions to the temperature response (and hardness after artificial aging) of an L- shaped Al 2024- T6 extrusion to quenches with multiple, overlapping water sprays. The validation study reported herein concludes by exploring the possibility of applying quenching technology to improving the properties of extruded metal- matrix composites such as SiC_p/Al 6061 and cast alloys.     

热喷锌、冷喷锌与富锌涂料三种涂层的耐蚀性对比

通过厚度测量、腐蚀电位测试和盐雾试验对钢铁结构腐蚀防护中常用的热喷锌、冷喷锌和富锌涂料三种涂层的耐蚀性进行了对比研究。结果表明:热喷锌涂层厚度不均匀,致密性差,盐雾试验21d后,涂层以点蚀的形式失效;富锌涂料涂层的腐蚀电位高于另外两种涂层的,在湿热盐雾环境中,鼓泡导致涂层和基体脱离而失去保护作用;冷喷锌涂层的厚度均匀,与基体结合力强,具有自修复能力和最好的耐蚀性。     

输入轴的防渗碳涂料自动涂敷设备设计开发和应用

通过设计开发输入轴防渗碳涂料自动涂敷专用设备,它可靠性、可控性、再现性、重复性、安全性、维修便捷性好,并开发出一套完整的涂敷工艺,经过反复验证,符合防渗碳范围的技术要求、重现性好。     

耐久超疏水涂层的制备及其防冰防腐自清洁性能

超疏水涂层在防结冰、防腐蚀等领域具有广阔的应用前景,然而目前仍无法大规模制备稳定的超疏水表面。提出一种操作简单、成本低廉的方法,在铝合金基材上通过一步喷涂法制备出耐磨超疏水涂层。首先在铝合金基体表面涂覆环氧树脂粘结层,待其达到半固化状态时,喷涂硬脂酸修饰的微米 SiO₂ 和纳米 TiO₂ 粒子混合悬浮液,固化后该涂层与水的接触角为~ 155.4°,滚动角为~3°,实现了超疏水性。试验结果表明,该超疏水涂层具有较好的耐磨耐久性,在胶带剥离、砂纸摩擦、 紫外光长时间照射以及不同 pH 液滴等多种测试条件下仍具有良好的超疏水性。此外,此超疏水涂层在极端寒冷的天气下可以显著延缓水的冻结时间。环氧树脂和疏水颗粒的协同防腐作用使超疏水涂层在海水中表现出良好的防腐蚀性能。所制备的超疏水涂层还具有优异的自清洁特性,且因 TiO₂ 粒子本身的光降解性能,该涂层还可用于光降解污染物和净化水质。这种简单、环保的超疏水涂层在防结冰、防腐蚀等方面具有潜在的应用前景,可为克服传统超疏水表面使用耐久性差的问题提供解决思路。     

Materials issues in microelectromechanical devices: science,engineering, manufacturability and reliability

MicroElectroMechanical Systems (MEMS) technology offers considerable potential throughout the manufacturing sector, because of certain intrinsic advantages in terms of low cost, reliability, and small size. Relatively simple MEMS are used in applications ranging from automobile air bag sensors to electronic games. Considerably more complex devices have been designed for defense applications, for which government funding is available; however, the fledgling industry suffers from insufficient knowledge of materials physics at micrometer size and from the fact that currently commercialized MEMS devices are designed for specialized and rather disparate purposes, do not have a broad user base, and therefore have not generated industry standards or the design and process software that would be built upon those industry standards. In addition to industry standards, further advances in MEMS technology require a more complete understanding of the physics underlying performance and reliability. The first half of this paper reviews general issues related to fabrication and commercialization; the second half addresses the technical materials issues that relate to MEMS performance and reliability.     

WC-Ni增强Fe基梯度涂层的制备及组织性能*

利用等离子熔覆同轴双筒送粉工艺,在Q235基板上制备了多层WC-Ni成分渐变的梯度涂层,结果表明:涂层中WC颗粒大部分被溶解,在随后的快速冷却中,有两类碳化物组织析出,组织特征与WC-Ni的含量有关。当WC-Ni含量小于20%时,析出粗大树枝晶基体混合片层状共晶碳化物组织;当WC-Ni含量大于30%时,析出块状初生碳化物组织。未完全溶解的WC颗粒呈圆角形,并与基体之间形成合金过渡层。梯度涂层中各层间形成了冶金过渡,其主要物相有γ-Fe、WC、Fe3C、Fe3W3C、Cr7C3。涂层的硬度明显高于基体,但受WC的溶解及析出碳化物的大小及分布不均影响,梯度涂层的硬度分布波动起伏较大。     

输送流体管道的沥青防腐层寿命、破坏原因及其危害

本文重点分析了影响沥青防腐层寿命与破坏的影响因素，局部破损的巨大危害及其避免方法，检查的方法，强调了管道的回填必须按照有关规范要求严格执行及其道理。