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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 ?
This is a strategic use of macrostructure by the author to promote the existence of IFC to the readers as an organization which will support them if they want to renounce the religion.
Up to the present time, there has been a limited amount of research work concerning discourse macrostructures of first language readers, and even fewer studies in the area have been conducted with second or foreign language students.
Newspaper: <<La Cuarta>> Date: 11-06-2008 Page: 8 Meaning / Thematic plane: global meanings text plane In correspondence between the heading and the rest of the macrostructures of the piece of news, they are trying to picture the offender as a person whose social plane is low because he is Peruvian, needs a wheelchair, and is taking advantage of his condition to bring drugs into Chile.
Here the cells were either freely suspended in the liquid or could be anchored to beads, but no large macrostructures were developed.
Apart from formal schemata, having to do with the text structuring, readers who apply genre-related strategies (overt recognition of genre type and conventions) are also better at getting the texts macrostructures through summarising in their own mother tongue (following indications in Bernhardt 1991 on the use of spreadsheet templates to get the text macrostructure with the main idea units).
To date, however, performance, production and cost limitations have prevented the successful integration of CN macrostructures into large-scale trials.
Les facteurs ecologiques incluent les flux d'energie (par exemple, l'intensite de l'energie solaire), les cycles geochimiques (comme le cycle du carbone), les fonctions biologiques (les types de vegetation, par exemple) et les macrostructures (comme la topographie).
Il s'agit d'une contribution au debat sur la differenciation agraire dans les societes postsocialistes en argumentant que, dans les endroits oo l'economie de marche est devenue plus developpee et qui sont proches des marches des villes, les changements au sein des macrostructures accentuent les differences de revenu, alterent les bases et les mecanismes de la differenciation, aussi bien que les modeles de differenciation existants.
All the pre-production elements of casting, set-design, lighting, and film stock testing continue, but digital technologies now allow attention to be paid to micro-levels of the image as well its macrostructures.
Second, the same process is followed between the various macrostructures of the text, and results in displaying the theme(s) and macrostructure(s) of the complete text (TTh, TMcr).
She deserves admiration both for her brilliant Lisztian technique and her ability to shape and model the macrostructures of the music while at the same time (as we have come to take for granted in her case) to pay perfect attention to detail.