Effect of cast copper and bronze structure on the value of their thermal expansion coefficient
DOI:
https://doi.org/10.34185/1991-7848.2018.01.07Keywords:
Copper, bronze, alloy, shrinkage, microstructure, grain, solidification, melt, chill moldAbstract
The magnitude of the coefficient of thermal linear expansion mainly depends on the temperature and phase composition of the material, the formation of which is determined not only by the chemical composition of the casting, but also by the conditions of its solidification. The objective of the research is to determine the influence of the solidification conditions of metals and alloys on the magnitude of their CTLR in the field of the elastic state of cast copper and its alloys. Research task of this work was to determine the influence of metals and alloys solidification conditions on the value of their CTLE in elastic state region of cast copper and its alloys. Results of these study investigations indicate that during cooling in casting mold temperature transition of technical purity copper from plastic to elastic state is 2860С. Accordingly, these values in bronzes: BrA5 ~426°С, BrA9Zh3L ~359°С, BrO5Z5S5 ~312°С. Variation in the values of thermal linear expansion coefficients of copper and its alloys which solidified under conditions of free and absolutely hindered linear shrinkage is due to differences in morphology and spatial orientation of crystals formed in alloys, as well as the fractional phases’ composition and defectiveness of the crystal structure.
References
LivarnI vlastivostI metalIv i splavIv dlya pretsizIynogo littya: pIdruchnik dlya vischih uchbovih zakladIv. / V.O. BoguslaEv, S.I. Rep'yah, V.G. Mogilatenko, Z.A. Ivchenko ta In.; pId red. S.I. Rep'yaha ta V.G. Mogilatenka; 2-e vid., dop. ta doopr. – ZaporIzhzhya: AT “MOTOR SICh”, 2016. – 474 s.
Mazorchuk V. F. Koeffitsientyi termicheskogo lineynogo rasshireniya litogo olova, alyuminiya i splava AL2 / V.F. Mazorchuk, K. I. Uzlov, S. I. Repyah, A.V. Dzyubina. – Teoriya i praktika metallurgii, 2017, # 3-4 (110-111). – S. 125-128.
Kazantsev E. I. Promyishlennyie pechi: sprav. ruk. dlya rasch. i proekt. / E. I. Kazantsev; 2–e izd., pererab. i dop. – M.: Metallurgiya, 1975. – 368 s.
GOST 859-2001 Med. Marki
GOST 18175-78 Bronzyi bezolovyannyie, obrabatyivaemyie davleniem. Marki.
GOST 493-79 Bronzyi bezolovyannyie liteynyie. Marki.
GOST 613-79 Bronzyi olovyannyie liteynyie. Marki.
ASM Metals Handbook. Volume 03: Alloy Phase Diagrams / ASM International. – Rezhim dostupu: http://www.asminternational.org/search/journal_content/56/10192/25871543/PUBLICATION
Bunin K.P. Metallografiya /K. P. Bunin, A. A. Baranov.– M.: Metallurgiya, 1970.– 256s.
Leybenzon V.O. Tverdnennya metalIv I metalevih kompozitsIy / V.O. Leybenzon, V.L. PIlyushenko, V.M. Kondratenko ta In.. – KiYiv: Naukova dumka, 2009. – 446s.
