钛铝化合物综述(二)——文献综述

在过去十年中,共公开发表过十五篇有关钛铝化合物结构和性能的研究论文。在先这些论文都未曾被综述过。这次讨论会提供了一次机会,使我们得以对钛铝化合物的科学的现状进行评述,并指出一些有待深入了解的领域。那些论文自然地分成若干领域,这就要求这篇综评也分成相应的领域。     

Thermodynamic analysis of inclusion in weld

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RELATIONSHIP BETWEEN PRIMARY MORPHOLOGY AND CRYSTAL STRUCTURE OF CARBIDES GROWING IN SUPERALLOYS

The SEM analysis of decply etched specimens of Ni-base superalloys K38 and K19H+Ta in-dicates that both the primary morphologies under normal growth conditions and the finalmorphologies near equilibrium of MC carbides are octahedral blocks.The classification ofMC crystal faces by means of PBC(Periodic Bond Chains)theory confirms that{100},{110}and{111}are F faces,and that{212}are S faces.The calculations of the attachmentenergy for each F face show that{111}are most easily appeared.It has also been inferred thatone of the MC growth units is a coordination octahedron composed of one metal atom sur-rounded by six carbon atoms.The octahedral growth units can be attached to the growth sur-faces of MC carbides through laver stacking mechanism on the{111}faces.     

世界镁工业现状

对1987年世界金属镁产量继续下跌的预测没有实现,尽管美国犹他州的阿马克斯(Amax)镁厂遭受了较大的洪水,但其产量仍上升了2～4％。美国矿务局估计数字表明,将比1986年增产4500吨,达到127500吨,而该公司估     

直接还原法生产铝硅合金(2)

4.熔炼合金的电炉矿石还原电炉,根据制取某种合金成分的还原过程的特有条件,其容量可设计成从5000KVA到100000KVA以上。这种炉子具有圆形、椭圆形或长方形炉膛,炉膛内通常设有3个或6个电极。熔炼铝硅合金与已知的铁合金过程比较,在大电流情况下,要求更低的电压。提高电压     

铝电解槽烟气干法净化—新型气/固反应器的设计和运行特性

序言干法净化电解车间烟气用的氧化铝,吸附有烟气中的杂质。如很细的金属化合物粒子、二氧化硫和由阳极带入的碳素材料。当净化器捕集的氧化铝返回电解槽时,这些固体杂质也进入电解槽,其中有的成份能使铝的纯度降低。如果生产用的氧化铝百分之百用于净化,这些     

碳在钢的气相渗碳中的传递模型

一些重要的渗碳与脱碳反应是用1010钢的薄片在保持流速不变的控制气氛管式炉中研究测定的。在小型的商业渗碳炉中所得到的渗碳数据进一步证实在典型炉气的气氛系中 CO 与 H_2化合而形成 C 与 H_2O 是碳传递到工件的主要反应。为富化而导入炉内的碳氢化合物由于触媒裂解反应,一开始就将碳沉积在加热表面上,由于加热表面和零件之间的温度差异,在使碳传递到被渗零件反应表面的过程中,CO—H_2反应起着一个“碳     

Fabrication of niobium doped Pb（Zr, Ti）O3 fibers by viscous polymer processing

A technique based on viscous polymer processing （VPP） was described, which can produce high ceramic content green fibers. PZT-5 ceramic powders were ball milled to get high dispersibility. The slurry prepared for VPP was a composition of PZT-5 powder, PVA binder and glycerin. High ceramic content PZT-5 fibers were extruded with the slurry. The results show that the ceramic powders have fine mean particle size of 0.54 pan, high specific surface area of 3.55 m^2/g and zeta potential of 8.81 mV after 16 h milling. The fibers sintered at 1 280 ℃ for 4 h have pure perovskite structure and grains of 2-5 μm in size, with little pores or cracks. The ultimate tensile strength of sintered fibers is up to 13.84 MPa compared with 2.88 MPa of green fibers. The remnant polarization （Pr） and coercive field （Ec） of the fibers are 50.65 μC/cm^2 and 2.45 kV/mm, respectively. This fiber can withstand an electric field of 9 kV/mm higher than the ceramic （5 kV/mm）, which shows high directional and compact qualities.     

Thermal Shock Property of Al/Ni-ZrO_2 Gradient Thennal Barrier Coatings

THERMAL BARRIER COATINGS can holdbackintrusion of high temperature,high heat to increaseapplied temperature and life of substrate metal parts,and have been applied on heat position of rocket,satellite,aero engine and gas engine"31.But thermalstresses are produced during thermal shock due tomismatch of thermal properties between ceramiccoatings and substrate metal,therefore thermal shockproperties of coatings are very poor.Gradient thermalbarrier coatings make materials gradually chang…     

完整生产线上的现代化铝带冷轧机

铝及铝合金带材和箔材轧制工艺的发展已经持续了几十年。这种进展的的标志是发明了各种尺寸和不同类型的轧机。至六十年代初,二辊和三辊轧机的条式或叠板轧制已完全被在工作辊直径小的四重机架上的带式轧制所取代;六十年代后期这种带式轧制的技术水平还处于卷重仅几百公斤(译者注: