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Structure of an etched metal visible to the naked eye or at magnifications up to 10 diameters.
(science and technology)
The external forms of a structure that can be observed without magnification, for example, the cubic crystal form of sodium chloride.



(of a metal), the structure of a metal that is visible visually or under a magnifying glass (that is, under magnification of up to 25 X). The macrostructure is studied in flat samples, called templates, cut from an item or blank, and also on the fracture surfaces of articles. To reveal the surface structure of a template, it is polished carefully and then etched with solutions of acids or alkalies.

The study of the macrostructure reveals discontinuities in the metal (cavities, porosity, gas bubbles, stratification, and fissures), distribution of impurities and nonmetallic inclusions, shape and distribution of crystallites (grains) in various parts of the item, and sometimes even the structural features of individual grains of the metal. Studies of the macrostructure lead to conclusions on the quality of initial materials and the correctness of the conduct of casting, pressure working, and welding processes. In some cases the quality of metals is characterized by the type of fracture, which makes possible determination of the path of the plane of fracture (through the body or along the grain boundaries) and of the causes of fracture.


References in periodicals archive ?
It was more specifically hypothesized that children who do not produce macrostructure miscues would be better equipped to adapt extensive text disruptions.
However, the macrostructure of the conifer genome has been remarkably stable over the ages," adds the professor from the Universite Laval Faculty of Forestry, Geography, and Geomatics.
Being able to determine the most important content, or macrostructure, of any written discourse is viewed as important in text processing (van Dijk & Kintsch, 1983; Kintsch, 2004; van den Brock et al.
Petroleum heavy ends stability: Evolution of residues macrostructure by ageing // Energ.
Decreasing the dielectric constant of the solution increased the intermolecular interaction between the particles and a greater tendency to form regular crystalline macrostructure with smaller sizes.
By sufficient increasing it clearly show that macrostructure of biopolymer composites is porous multilevel structure, where particles HA are connected among themselves by polymer binder.
Unlike the early ethnomethodologists, who dismissed all macrostructure as rhetorical gloss and concentrated instead on the patterns of situated cognition, I am quite willing to admit that macropatterns exist--as chains of microinteraction.
The macrostructure of bamboo-stem is similar to many species of grass family with distinct nodes and internodes.
The papers have been organized into sections on casting, coupling/multi-physics, defect formation, fluid flow, micro and macrostructure formation, numerical methods/segregation, welding, and phenomena in solidification modeling and validation.
Algal morphology refers to the algal macrostructure, which can be distinguished under a dissecting microscope, and does not include the microstructure of the algal surface in this study.
2006b) studies have found age-alcoholism interactions in the macrostructure of the corpus callosum.
Next, the macrostructure of a wordnet in terms of its integration and compatibility with other wordnets is investigated, arter which the proposed methodology is presented with a discussion of the results.