爆炸粉末冶金 第一部分

爆炸粉末冶金作为一种难熔金属和超合金潜在的加工技术,本文作了介绍。这些材料的难加工性向加工工业提出了挑战。本文介绍了一种球形爆炸压制装置,以期概括地描述一下工业生产所需的参数,并得出与圆柱形爆炸压制方法的相互关系。     

氧化铝生产中压煮溶出过程的强化

压煮溶出过程广泛用在:拜耳法生产氧化铝中的铝土矿溶出、高硅铝土矿和霞石生产氧化铝时的脱硅、霞石正长岩的化学选矿、以碱法和酸法处理劣质铝矿原料时的原料分解以及水解析出铝化合物等。苏联和其它一些国家都是用压煮器组溶出     

氧化铝—碳化铌复合材料的烧结

为了提高室温和高温下的机械性能和时磨性能，对颗粒弥散氧化铝复合材料进行了一系列研究。在本研究中，对Al2O3—NbC复合材料无压烧结，并对其显微结构与NbC和Y2O3含量的函数关系进行了分析。Y2O3用作烧结辅助剂，本研究中使用的成分是Al2O3、xNbC和(Al2O33％Y2O3)-xNbC(x=10％，20％和40wt％)。烧结是在1650℃／30分钟和1750℃／15分钟条件下完成。对于1650℃烧结的材料相对密度高于理论密度的96%。发现有Y2O3添加剂试样的显微结构更加均匀，而且检测到了Y3Al5O12相。NbC浓度抑制了Al2O3晶粒长大．这在1750℃烧结的试样中更为明显．     

高强铝合金反向挤压的经验

七十年代初期至中期,许多文章对反向挤压的设备、工艺和冶金学方面进行了探讨.然而这些研究工作大多是在300-800吨的较小试验设备上进行的.这期间,美国、日本和欧洲有不少正向挤压机改用反向挤压工艺,此外,近年内又安装了新的反向挤压机,最大挤压力达6600吨.这些挤压机的运行经验表明,并不是在试验设备上获得的所有成果都能毫无问题地照搬到大型挤压机上,因为大挤压机上反向挤压的优缺点与小试验设备上的有部分区别.     

Laser Cladding of an Al-11.7Wt%Si Alloy on ZM5 Magnesium Alloy to Enhance the Corrosion Resistance

MG and its alloys are widely used in aerospace andautomotive in industry.Its poor corrosion resistancerestricts application of Mg alloy.Laser cladding andlaser surface melting are advantageous processes forimprovement of the corrosion resistance of themagnesium alloy[1-2].In the present study,lasercladding of an Al-11.7Wt%Si alloy with two differentthickness on ZM5die cast alloy was performed withCC>2laser with different powder thickness.1.Experimental ProcedureDie cast plates of ZM5Mg a…     

连续铸造时铝合金的结晶方式和显微组织

由于枝晶网尺寸或枝晶间距同局部凝固时间之间有确定的关系,所以则有可能根据铸态显微组织计算凝固热参数。在不同类型的铝锭(各种直径的直接水冷铸锭,普通模和电磁模铸造的铸锭,辊式、带式及板式铸造机铸出的带板以及Properzi法铸造的棒,横断面上测量枝晶间距,以此作为计算的基础。根据测量结果,本文定性地讨论了铝锭凝固过程中的结晶热参数以及铸造条件对结晶热参数的影响。     

Ni/Al Intermetallics Plasma Transferred Arc Processing

TAILORING COMPONENT SUFACES for elevatedtemperature operations has been a goal of researchersduring the last century.Process and material selectionare the key factors for this development.In particularlythe latter can be described to have started with thedevelopment of stainless steels.Ni and Co based alloys,the superalloys,attended the increasing technologicaldemands for higher service temperatures(1).Morerecently the higher operating temperatures ofequipments,such as gas turbines,r…     

含硫、氧的球墨铸铁孕育剂

常规的球墨铸铁生产中，铁中能否有硫化物和氧化物作为石墨结晶的核心，取决了原铁水的纯度和添加剂、保持时间和温度以及冶金处理工艺和添加剂。     

Effect of copper addition on the thermal contraction of indium melt clusters

The structure of In-1%Cu and In-5%Cu (mass fraction) alloy melts were studied at different temperatures above liquidus by using a high-temperature X-ray diffractometer and were compared with that of pure In melt. Experimental results show that with the addition of 1% Cu or 5% Cu, the thermal contraction phenomenon of atom clusters occurs in melts with the temperature increasing like pure In melt. With the addition of 1% Cu, the thermal contraction of atom clusters increases and the contraction is not homogeneous in the whole measurement temperature range. The sudden change and noticeable contraction can be found in the range of 280-390℃. The temperature range of the sudden change is lower than that of pure In melt. With the addition of 5% Cu, the thermal contraction of atom clusters decreases and the contraction is not consistent in the whole measurement temperature range. The anomalous change can be measured at about 600 ℃. At the same superheating temperature, the nearest interatomic distance r1 of     

INTRODUCTION TO INCONEL ALLOY 740: AN ALLOY DESIGNED FOR SUPERHEATER TUBING IN COAL-FIRED ULTRA SUPERCRITICAL BOILERS

1. IntroductionW hile w orldw ide environm entalrestrictionsare requiring pow ercom paniesto reduce SO x,N O x andCO 2 em issions, econom ic pressuresare sim ultaneously necessitating im provem entsin the therm aleffi-ciency ofallcoal-fired plants. A ddin…