Metal age

Kalt-absetzen, n. cold settling or sedimentation, -aushartung, /. (Metal.) age hardening at room temperature cold tempering, -bad,... 

Das, Chang, Raybould High Performance Magnesium Alloys by Rapid Solidification Processing , Light Metal Age, Dec. 5-8 1986... 

The results of this work suggest that the greatest contaminant metals effects are due not only to the most recently deposited metals, but to those recently deposited metals which are present on the most recently added zeolitic particles (i.e., those containing the most zeolite). At constant metals aging then, the contaminant selectivities due to nickel and vanadium are in a large part determined by 1) the presence or absence of zeolite in the particle 2) the non-zeolitic surface area of the particle and 3) the chemical composition of the particle. 

In general, although proper metal aging is still an open issue, it seems that severe hydrothermal conditions during ReDox cycles with an emphasized reducing step is the direction to optimization of the artificial deactivation methods. The development of such a simulative lab-deactivation protocol will undoubtedly be very essential and a major contribution in the FCC research field. 

A Cyclic Deactivation procedure will be preferred in order to simulate the actual metal distribution and interactions on the catalyst and the correct metal age distribution [2, 23, 27, 34]. 

The oxidative binder samples of Estane/NP were placed in glass ampoules and flame sealed under argon. Tensile specimens were placed in metal aging chambers, evacuated and back filled with argon to provide a dry oxygen free environment. The samples were placed in aging ovens at 55, 65 and 75°C and removed periodically for analysis. 

The distribution and the effect of metals in CD samples can be explained by a coupling of the time basis for metal deposition and the kinetics of metal aging. Especially the requirement for Vanadium is longer compared to that of nickel as the former needs somewhat special conditions to produce mobile reactive species [4]. Simply put, the ratio of the aging time to the metal addition... 

The properties of a commercial FCC catalyst modified with V and Ni by cyclic deactivation (CD) and impregnation-based laboratory procedures were compared to the properties of equilibrium catalysts tested in a commercial FCC unit. Principle differences were the degree of metal aging and concentration profiles in the catalyst particles. The CD procedure produced properties in the catalyst that were comparatively closer to those exhibited by the equilibrium catalysts. 

Differences in MAT numbers between oxidized and reduced catalysts are proposed to be related to the extent of metal aging. Metals were comparatively more active in the metallated samples than in the equilibrium catalysts. Although this was less evident for the catalyst deactivated by CD, it was observed that the metal aging procedure failed to reproduce completely the state of metals found in equilibrium catalysts. Therefore the aging process of deposited metals still remains a key factor for simulating more closely the properties of FCC equilibrium catalysts. 

Vanadium interacts with nickel in a manner which inhibits the deactivation behavior of nickel. Metals-resistant catalysts must therefore be evaluated in the presence of both nickel and vanadium. Also, the mobility of vanadium is reduced in the presence of nickel. In general, cyclic deactivation will be the preferred deactivation method in order to simulate the actual metal distribution and interactions on the catalyst and the correct metal age distribution. 

A comparison of tensile curves of as-received base metal, aged base metal, and aged weld samples is shownin the plotinFig. 7.28. Average tensile results for each of these conditions are sum-... 

A catalyst is a substance that changes the speed of a chemical reaction without undergoing a permanent chemical change itself. Most reactions in the body, the atmosphere, and the oceans occur with the help of catalysts. Much industrial chemical research is devoted to the search for more effective catalysts for reactions of commercial importance. Extensive research efforts also are devoted to finding means of inhibiting or removing certain catalysts that promote undesirable reactions, such as those that corrode metals, age our bodies, and cause tooth decay. 

Much information is available on ageing problems of NPPs. Extensive programmes are being conducted in the IAEA and in its Member States. The objectives of many of the studies are metal ageing (mostly steels) and degradation of concrete structures, electrical equipment, electronic components, elastomers and lubricants. Most of this research has been carried out in research reactors, some of them almost exclusively dedicated to material testing (see Appendix IV). 

H0y-Petersen N (1990) From past to future. Light Metal Age 48 14-16... 

Nevertheless, if we generalize the chances of polymer carbon and composites in the future one could prognose with some imagination, that the metal age never has been replaced by a polymer age so far, but will be replaced in future by a carbon age with the support of polymers. 

Bunch, B. H., and A. Hellemans. 1993. The Timetables of Technology A Chronology of the Most Important People and Events in the History of Technology. New York Simon Schuster. This work devoted to the history of technology is divided into seven time frames the Stone Ages (2,400,000-4000 BCE), the Metal Ages (4000 BCE-1000 CE), the Age of Water and Wind (1000-1732), the Industrial Revolution (1733-1878), the Electric Age (1879-1946), the Electronic Age (1947-1972), and the Information Age (1973-1993). Included are a name index and a subject index. 

E. M. Gutman, Ya. Unigovski, A. Eliezer, E. Abramov, L. Riber, Effect of processing and environment on mechanical properties of die cast magnesium alloys. Light Metal Age, (December 2000), 14, 15, 16-20. 

Kotler, G L, Hawke, D L Aqua, E N (1976a), MGZ coating process for magnesium and its alloys . Light Metal Age, 34, 20-21. 

The beginning of the Metal Age is, however, probably more properly associated with the first extraction of metal from ore. Some writers believe that lead, rather than copper, can lay claim to being the first of the metals to be smelted by man, as long ago as 7000 BC. Lead ore (most commonly, galena or lead sulphide) would certainly have been the simplest for early man to smelt, requiring much lower temperatures than other metallic ores and a more straightforward extraction process. Further, given the abundance of copper in its native state to early man, there would have been little incentive... 

Figure 1.96 Super light weight aluminum Uthium alloy fuel tank for space shuttle launches (Anon., 1998 reprinted by permission of light Metal Age).

Anon. (1998). Aluminum-Lithium Alloys. Light Metal Age 56(1 -2), 102-105. 

---