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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 ?
Figure 9 shows the macrostructure of welded samples joined with different welding currents.
Pour identifier les caracteristiques generales d'un grand corpus de presse, nous postulons d'abord l'existence, dans n'importe quel corpus, de macrostructures qui soutiennent les textes.
(1) Macrostructures show that both ingots are composed of columnar zone and dendritic zone, and the primary dendrite arm spacings are 353 [micro]m for the 30 [micro]m/s withdrawn ingot and 144 [micro]m for the 200 [micro]m/s withdrawn ingot, respectively.
We did not observe any difference between two groups in terms of the parameters of sleep macrostructure defined by conventional PSG scoring and clinical characteristics similar to several previous studies.
These results are also proved by the macrostructure having different oil phase contents but constant egg albumin (data not shown).
The analysis focused mostly on the three elements-Grammatical analysis, Macrostructures, and Rhetorical Structures.
Despite the fact that the macrostructure of Polish and British winding-up petitions differs in respect to the order of information and data, one may still compare terminology and grammatical structures used in those parallel texts.
By using optical microscopy, macrostructures of the friction stir processed samples were analyzed.
Moreover, unlike text 1, text 2 has a socio-semantic coherence that enriches its macrostructure on the semantic level.
Keywords: popular science; narrative macrostructure; reader engagement; narrative of discovery; discourse analysis; scientific writing
The research objective was to evaluate the chemical composition and macrostructure of hair concentrate produced from waste of skin crackers industry in various production processes.
These sites give rise to a metal conductor macrostructure inhomogeneous temperature fields, periodically changing along its length or radius.