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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 ?
The analysis focused mostly on the three elements-Grammatical analysis, Macrostructures, and Rhetorical Structures.
The macrostructure of British English winding-up petitions is the following:
The Explanation is not part of Labov and Waletzky's (1967) nor Labov's (1972) macrostructure of a narrative.
0]/n with n=1,3,9 in the 320, 107 and 34 mm, as well as an appearance in the macrostructure of the longitudinal wires inhomogeneous periodic temperature field with a temperature difference between its <<hot>> and <<cold>> longitudinal in about 1000[degrees]C.
It was found in Table 1, for expository text E1, when the total averages were compared among the variables, it was observed that the macrostructure literal questions (MaL) were higher than the average of the microstructure literals (MIL).
For example, the waves in hierarchically microstructured solids composed by a macrostructure and microstructures (the second one embedded into the first) are asymptotically described by
The Philharmonic String Quintet give preference to the compact sound of a chamber ensemble and observance of the macrostructure, while the Scharoun Ensemble thoroughly pursue the compositions' microstructure, differentiate the dynamics, apply sharper accentuation and savour details in articulation and phrasing.
The cross-linguistic approach adopted here, looking at the similarities and differences in the macrostructure of correspondence written home by envoys abroad, highlights one of the major advantages of volumes like this: a discovery of commonalities in Late Modern European letters, regardless of language.
In fact, as many students of the macrostructure of the Psalter have observed, the movement of the first three books of Psalms traces the breakdown of the Davidic monarchy as it moves from David at the end of Book I (41), to Solomon at the end of Book II (72), climaxing in Rehoboam's division of the kingdom and the Babylonian exile eventually fostered by that division at the end of Book III (89), which results in the loss of Davidic kingship.
Working in groups, the students were asked to examine the text that they had received and to decide which macrostructure was portrayed based on the vocabulary contained within.
These types of steels have high flexibility at macrostructure state, but their yield strength is rather low.