scholarly journals Drawing the Tensile Curve for Pure Metals and Alloys Depending On Crystal Structure and Acoustic Impedance

2021 ◽  
Vol 1076 (1) ◽  
pp. 012084
Author(s):  
Arshed Abdulhamed Mohammed ◽  
Wessam Al Azzawi
Keyword(s):  
Crystal Structure ◽  
Acoustic Impedance ◽  
Metals And Alloys ◽  
Tensile Curve ◽  
Pure Metals

Metallurgical Principles

Extrusion ◽  
2006 ◽  
pp. 141-194
Author(s):  
Martin Bauser
Keyword(s):  
Crystal Structure ◽  
Copper Alloys ◽  
Extrusion Process ◽  
Metals And Alloys ◽  
Crystal Defects ◽  
Metal Powders ◽  
Fracture Characteristics ◽  
Pure Metals ◽  
Weld Seams ◽  
Cast Microstructure

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.

scholarly journals Solidification of Metals and Alloys

2020 ◽  
Author(s):  
Upendra Kumar Mohanty ◽  
Hrushikesh Sarangi
Keyword(s):  
Crystal Structure ◽  
Liquid Metal ◽  
Growth Process ◽  
Metals And Alloys ◽  
Liquid Metal Surface ◽  
The Common ◽  
Pure Metals ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Rates Of Growth

In order to analyse the process of solidification of metals and alloys critically, it is most pertinent to understand the different modes of nucleation and the uneven rates of growth throughout the melt. It is also important to take a note of the constraints in the growth process that definitely influence the crystal structure and the structure related properties of the casting. The freezing pattern of the liquid melt decides the feeding of the mould which is instrumental in producing a complete and compact casting. For pure metals and even in case of alloys with a narrow freezing range a well defined solid–liquid macro-interface exists. Here feeding of the solidifying casting is the easiest, by the common lowering of the liquid metal surface in the mould. However, in many instances, a well defined interface is not witnessed. The solid–liquid interface could be discrete and not continuous. Here process of feeding the solidification sites that witness considerable shrinkages, may become complicated. On grounds of above it is implied, the process of solidification constitutes an important aspects in the production of a defect free casting.

scholarly journals The thermal conductivities of certain approximately pure metals and alloys at high temperatures

1931 ◽  
Vol 134 (823) ◽  
pp. 57-76 ◽  
Keyword(s):  
Heat Flow ◽  
High Temperatures ◽  
Heat Losses ◽  
Metals And Alloys ◽  
Maximum Temperature ◽  
Internal Heating ◽  
Heating Coil ◽  
Pure Metals ◽  
Guard Tube ◽  
Thermal Conductivities

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.

A dynamical model of a crystal structure - IV. Grain boundaries

1952 ◽  
Vol 212 (1111) ◽  
pp. 576-584 ◽  
Keyword(s):  
Crystal Structure ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Large Angle ◽  
Gradual Transition ◽  
Small Angle Boundary ◽  
Pure Metals ◽  
And Diffusion ◽  
Large Angle Boundary ◽  
Dislocation Walls

Four photographs of bubble rafts are used as a basis for discussion of the structure of grain boundaries in pure metals. In these photographs one can follow the gradual transition from a small-angle boundary made up of clearly separate dislocations to a large-angle boundary where the dislocation structure is hardly recognizable. As the angle is increased, a continuous shortening of the dislocations, accompanied by the widening of a crack on the tensile side, is seen, and the process culminates in a structure which is perhaps best described in terms of local fit and misfit. The fact is also illustrated that the dislocation content of the boundary depends on the angle of the boundary, as well as on the disorientation of the crystals that it separates. If a boundary turns it must therefore gain or lose dislocations. The bearing of this on the measurement of grain-boundary energies is discussed. Other points considered concern the range of validity of calculations of the energy of dislocation walls, and slip and diffusion along grain boundaries.

Sign in / Sign up

Export Citation Format

Share Document