Fabrication and characterization of ultra-fine grained tungsten by resistance sintering under ultra-high pressure

The Pauza ultramafic body is part of Upper Cretaceous Ophiolitic massifs of the Zagros Suture Zone, NE Iraq. The present study reveals evidence of Ultra-high pressure (UHP), and deep mantle signature of these peridotites in the Zagros Suture Zone throughout the observation of backscattered images and micro analyses which have been performed on orthopyroxen crystals in lherzolite of Pauza ultramafic rocks.Theorthopyroxen shows abundant exsolution lamellae of coarse unevenly distributed clinopyroxene coupled with the submicron uniformly distributed needles of Cr-spinel. The observed clusters of Opx–Cpx–Spl represent the decompression products of pyrope-rich garnet produced as a result of the transition from ultra-high pressure garnet peridotite to low-pressure spinel peridotite (LP). Neoblastic olivine (Fo92 – 93) with abundant multi-form Cr- spinel inclusions occurs as a fine-grained aggregate around orthopyroxene, whereas coarse olivine (Fo90-91) free from chromian-spinel is found in matrix. The similarity of the Cr-spinel lamellae orientations in both olivine and orthopyroxene, moreover, the enrichments of both Cr and Fe3+ in the Cr-spinel inclusions in neoblastic olivine relative to Cr-spinel lamellae in orthopyroxene, suggest that spinel inclusions in olivine have been derived from former Cr-spinel lamellae in orthopyroxene. Neoblastic olivine is formed by reaction of silica-poor ascending melt and orthopyroxene. It is inferred that the olivines with multi-form spinel inclusions has been formed by incongruent melting of pre-existing spinel lamellae-rich orthopyroxene.

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Fabrication and characterization of nanostructured immiscible Cu–Ta alloys processed by high-pressure torsion

Journal of Alloys and Compounds ◽

10.1016/j.jallcom.2020.155007 ◽

2020 ◽

Vol 832 ◽

pp. 155007 ◽

Cited By ~ 5

Author(s):

Tayebeh Mousavi ◽

Jiaoyan Dai ◽

Piotr Bazarnik ◽

Pedro Henrique R. Pereira ◽

Yi Huang ◽

...

Keyword(s):

High Pressure ◽

High Pressure Torsion ◽

Fabrication And Characterization

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Fabrication and characterization of fine-grained barium strontium titanate ceramics by the heterogeneous precipitation method

Journal of Materials Science ◽

10.1007/s10853-006-1291-1 ◽

2007 ◽

Vol 42 (16) ◽

pp. 6917-6922 ◽

Cited By ~ 2

Author(s):

Chaoliang Mao ◽

Xianlin Dong ◽

Tao Zeng ◽

Genshui Wang

Keyword(s):

Strontium Titanate ◽

Barium Strontium Titanate ◽

Precipitation Method ◽

Fine Grained ◽

Heterogeneous Precipitation ◽

Barium Strontium ◽

Fabrication And Characterization ◽

Titanate Ceramics

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Microstructure Development and Precipitation Effects in Ultra Fine Grained Mg-3Tb-2Nd Alloy Prepared by High Pressure Torsion

Materials Science Forum ◽

10.4028/www.scientific.net/msf.584-586.591 ◽

2008 ◽

Vol 584-586 ◽

pp. 591-596 ◽

Cited By ~ 2

Author(s):

Jakub Čížek ◽

Ivan Procházka ◽

Bohumil Smola ◽

Ivana Stulíková ◽

Martin Vlach ◽

...

Keyword(s):

High Pressure ◽

Positron Lifetime ◽

High Pressure Torsion ◽

Creep Properties ◽

Fine Grained ◽

Transmission Electron ◽

Highly Sensitive ◽

Ideal Tool ◽

Increasing Temperature

Mg-Tb-Nd ternary alloy represents a novel hardenable Mg-based alloy with enhanced strength and favorable creep properties. In the present work we studied microstructure of ultra fine grained (UFG) Mg-Tb-Nd alloy prepared by high pressure torsion (HPT). Lattice defects introduced into the specimen by the severe plastic deformation play a key role in physical properties of UFG specimens. It is known that positron lifetime (PL) spectroscopy is highly sensitive to open volume defects (like vacancies, dislocations, etc.). Therefore, PL spectroscopy is an ideal tool for defect characterizations in the HPT deformed specimens. In the present work we combined PL studies with transmission electron microscopy and microhardness measurements. After detailed characterization of the as-deformed structure, the specimens were step-by-step isochronally annealed and we investigated the development of microstructure with increasing temperature.

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