5.2 Data for pure metals and alloys

Author(s):  
B. Sundqvist
Extrusion ◽  
2006 ◽  
pp. 141-194
Author(s):  
Martin Bauser

Abstract This chapter explains the basic terminology and principles of metallurgy as they apply to extrusion. It begins with an overview of crystal structure in metals and alloys, including crystal defects and orientation. This is followed by sections discussing the development of the continuous cast microstructure of aluminum and copper alloys. The discussion provides information on billet and grain segregation and defects in continuous casting. The chapter then discusses the processes involved in the deformation of pure metals and alloys at room temperature. Next, it describes the characteristics of pure metals and alloys at higher temperatures. The processes involved in extrusion are then covered. The chapter provides details on how the toughness and fracture characteristics of metals and alloys affect the extrusion process. The weld seams in hollow profiles, the production of composite profiles, and the processing of composite materials, as well as the extrusion of metal powders, are discussed. The chapter ends with a discussion on the factors that define the extrudability of metallic materials and how these attributes are characterized.


Measurements have been made by several observers on the thermal conductivities of metals and alloys up to high temperatures. Heat losses to the surroundings become large at high temperatures, hence the guard tube method, which to a great extent eliminates these losses, has been popular for work at these temperatures. This method was described and used by Berget in 1888, and later by Wilkes. These observers measured the rate of heat flow by a calorimetric method, which is not suitable for work at high temperatures. Honda and Simidu, using an internal heating coil, determined the heat flow from the energy input and were able to obtain results for nickel and steel to over 800°C. More recently, Schofield, using the guard tube method with an internal heating coil, has obtained results up to a maximum temperature of 700°C. with five metals. The present work was undertaken with a view to continuing the work of Professor C. H. Lees on the effect of temperatures between —160°C. and 15°C. on the thermal conductivities of nine metals and six alloys.


2011 ◽  
Vol 33 (4) ◽  
pp. 4602-4302 ◽  
Author(s):  
Simón Reif-Acherman

Two different lines of research had significant contributions to the discovery of superconductivity: the liquefaction of gases and the studies of the temperature dependence of the electrical conductivity, or resistance, of pure metals and alloys. Different publications have described and discussed the achievements in the first one of these subjects. The second subject had not received, however, the same attention. This article tries to fill this gap by presenting an account showing details of the evolution of the ideas, the first essentially experimental contributions to the subject and their corresponding responsible persons.


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