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Author Martinez, C.; Briones, F.; Rojas, P.; Aguilar, C.; Guzman, D.; Ordonez, S.
Title Microstructural and mechanical characterization of copper, nickel, and Cu-based alloys obtained by mechanical alloying and hot pressing Type
Year 2017 Publication Materials Letters Abbreviated Journal Mater. Lett.
Volume 209 Issue Pages 509-512
Keywords BULK METALLIC GLASSES; CORROSION BEHAVIOR; THERMAL-STABILITY; AMORPHOUS-ALLOYS; GRAIN-SIZE; NANOCRYSTALLINE; CRYSTALLINE; HEAT
Abstract Mechanical alloying and uniaxial compaction were used to obtain configurations of: elemental powders of Cu and Ni; binary alloys (Cu-Ni and Cu-Zr); and a ternary alloy (Cu-Ni-Zr) under the same mechanical milling and hot pressing conditions. Microstructure and mechanical properties of these were investigated. According to XRD results, hot pressing process increases crystallite size and decreases microstrain in the compact samples, due to the release of crystalline defects without crystallization of amorphous alloys. The milled powder samples have a higher hardness than the unmilled samples, since crystal defects are incorporated into microstructural refinement during milling. The ternary alloy Cu-40Ni-10Zr had the highest hardness of all systems studied, reaching 689 HV0.5. Compression tests at 5% strain determined that Zr-containing samples (amorphous phase) become more fragile after processing, and have the lowest values of compressive strength. In contrast, Ni samples and Cu-Ni binary alloys are more resistant to compression. (
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0167-577X ISBN Medium
Area Expedition Conference
Notes WOS:000413124300129 Approved
Call Number UAI @ alexi.delcanto @ Serial 1409
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Author Martinez, C.; Briones, F.; Rojas, P.; Ordonez, S.; Aguilar, C.; Guzman, D.
Title Microstructure and Mechanical Properties of Copper, Nickel and Ternary Alloys Cu-Ni-Zr Obtained by Mechanical Alloying and Hot Pressing Type
Year 2017 Publication MRS Advances Abbreviated Journal MRS Adv.
Volume 2 Issue 50 Pages 2831-2836
Keywords BULK METALLIC GLASSES; GRAIN-SIZE; NANOCRYSTALLINE MATERIALS; AMORPHOUS-ALLOYS; PROFILE ANALYSIS; BEHAVIOR; POWDERS; WEAR
Abstract Elemental powders of Cu and Ni, binary alloys (Cu-Ni and Cu-Zr) and ternary alloy (Cu-Ni-Zr) obtained by mechanical alloying and uniaxial compaction hot microstructure and mechanical properties were investigated. The alloys studied were: pure Cu, pure Ni, binary alloys (Cu-Ni; Cu-Zr) and ternary alloys (Cu-Ni-Zr) under the same mechanical milling and hot pressing conditions. The samples were analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM); the mechanical properties were studied by compression tests and hardness in Vickers scale (HV0.5) on polished surfaces at room temperature. According to XRD results, hot pressing process crystallite size increase and microstrain decreases in the compact samples due to the release of crystalline defects. The compacted samples have porosity of approximately 20%. The milling powder samples have a higher hardness than the unmilled samples, this because during milling crystal defects are incorporated together with the microstructural refinement. Ternary alloy is the one with the highest hardness of all systems studied, reaching 689 HV0.5. In compression tests determined a strain 5 %, Zr-containing samples become more fragile presenting the lowest values of compressive strength. In contrast, samples of Ni and Cu-Ni binary alloy are more resistant to compression.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2059-8521 ISBN Medium
Area Expedition Conference
Notes WOS:000412784800004 Approved
Call Number UAI @ alexi.delcanto @ Serial 1410
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Author Rojas, P.A .; Martinez, C.; Aguilar, C.; Briones, F.; Zelaya, M.E.; Guzman, D.
Title Characterization of phase changes during fabrication of copper alloys, crystalline and non-crystalline, prepared by mechanical alloying Type
Year 2016 Publication Ingenieria E Investigacion Abbreviated Journal Ing. Invest.
Volume 36 Issue 3 Pages 102-109
Keywords EXTENDED SOLID SOLUBILITY; CU-ZR BINARY; NANOCRYSTALLINE METALS; BEHAVIOR; POWDERS; SYSTEM; DISPERSION; GLASS; SIZE; TI
Abstract The manufacture of alloys in solid state has many differences with the conventional melting (casting) process. In the case of high energy milling or mechanical alloying, phase transformations of the raw materials are promoted by a large amount of energy that is introduced by impact with the grinding medium; there is no melting, but the microstructural changes go from microstructural refinement to amorphization in solid state. This work studies the behavior of pure metals (Cu and Ni), and different binary alloys (Cu-Ni and Cu-Zr), under the same milling/mechanical alloying conditions. After high-energy milling, X ray diffraction (XRD) patterns were analyzed to determine changes in the lattice parameter and find both microstrain and crystallite sizes, which were first calculated using the Williamson-Hall (W-H) method and then compared with the transmission electron microscope (TEM) images. Calculations showed a relatively appropriate approach to observations with TEM; however, in general, TEM observations detect heterogeneities, which are not considered for the W-H method. As for results, in the set of pure metals, we show that pure nickel undergoes more microstrain deformations, and is more abrasive than copper (and copper alloys). In binary systems, there was a complete solid solution in the Cu-Ni system and a glass-forming ability for the Cu-Zr, as a function of the Zr content. Mathematical methods cannot be applied when the systems have amorphization because there are no equations representing this process during milling. A general conclusion suggests that, under the same milling conditions, results are very different due to the significant impact of the composition: nickel easily forms a solid solution, while with a higher zirconium content there is a higher degree of glass-forming ability.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0120-5609 ISBN Medium
Area Expedition Conference
Notes WOS:000392963200014 Approved
Call Number UAI @ alexi.delcanto @ Serial 1411
Permanent link to this record