Characteristic Scales on Pure Nickel-Chromium Alloys at 800°–1200°C

1966 ◽  
Vol 113 (4) ◽  
pp. 319 ◽  
Author(s):  
G. C. Wood ◽  
T. Hodgkiess
Keyword(s):  
Pure Nickel ◽  
Nickel Chromium ◽  
Chromium Alloys ◽  
Characteristic Scales

HREM observation of NiO growth on submicron spheres of pure nickel

1989 ◽  
Vol 47 ◽  
pp. 548-549
Author(s):  
C.M. Teng ◽  
T.F. Kelly ◽  
J.P. Zhang ◽  
H.M. Lin ◽  
Y.W. Kim
Keyword(s):  
Nickel Oxide ◽  
Grain Boundaries ◽  
Pure Nickel ◽  
Submicron Particles ◽  
Crystal Formation ◽  
Nickel Wire ◽  
Liquid Droplets ◽  
Oxide Interface ◽  
Nickel Chromium ◽  
Chromium Alloys

Spherical submicron particles of materials produced by electrohydrodynamic (EHD) atomization have been used to study a variety of materials processes including nucleation of alternative crystallization phases in iron-nickel and nickel-chromium alloys, amorphous solidification in submicron droplets of pure metals, and quasi-crystal formation in nickel-chromium alloys. Some experiments on pure nickel, nickel oxide single crystals, the nickel/nickel(II) oxide interface, and grain boundaries in nickel monoxide have been performed by STEM. For these latter studies, HREM is the most direct approach to obtain particle crystal structures at the atomic level. Grain boundaries in nickel oxide have also been investigated by HREM. In this paper, we present preliminary results of HREM observations of NiO growth on submicron spheres of pure nickel.Small particles of pure nickel were prepared by EHD atomization. For the study of pure nickel, 0.5 mm diameter pure nickel wire (99.9975%) is sprayed directly in the EHD process. The liquid droplets solidify in free-flight through a vacuum chamber operated at about 10-7 torr.

scholarly journals The Importance of Phase Composition for Corrosion Resistance of Borided Layers Produced on Nickel Alloys

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5131
Author(s):  
Natalia Makuch
Keyword(s):  
Corrosion Resistance ◽  
Phase Composition ◽  
Nickel Alloys ◽  
Chromium Content ◽  
Pure Nickel ◽  
High Susceptibility ◽  
Nickel Chromium ◽  
Chromium Alloys ◽  
Plasma Paste Boriding ◽  
Boriding Process

The plasma paste boriding process was used for production of the borided layers on pure nickel and nickel-chromium alloys. The produced layers consisted of nickel borides only (in the case of nickel) or a nickel and chromium borides mixture (in the case Ni–Cr alloys). The objective of this investigation was to indicate the importance of the presence of chromium for corrosion resistance of non-borided alloys, as well as to indicate the influence of phase composition of borided layers on their corrosion resistance. Pure nickel was characterized by higher corrosion resistance, in comparison to the nickel-based alloys. Increased chromium content in nickel alloys resulted in their high susceptibility for pitting corrosion. All borided samples were characterized by higher corrosion resistance than the non-borided samples. However, the phase composition of borided layers influenced their corrosion resistance. Due to the microstructure which consisted of one type of borides (nickel borides), borided nickel had the highest resistance to corrosion, whereas the presence of chromium borides in layers produced on nickel-chromium alloys caused a decrease in corrosion resistance.

Quasicrystal structures in submicron spheres of pure nickel and nickel-chromium alloys

1989 ◽  
Vol 47 ◽  
pp. 296-297
Author(s):  
Hong-Ming Lin ◽  
Thomas F. Kelly
Keyword(s):  
Intermediate State ◽  
Pure Nickel ◽  
Icosahedral Quasicrystal ◽  
Diffraction Ring ◽  
Rotation Symmetry ◽  
Nickel Chromium ◽  
Chromium Alloys ◽  
Fe Alloys ◽  
Crystal Grains ◽  
Diffraction Patterns

The icosahedral quasicrystal with a fivefold rotation symmetry was first reported in Al-M (M = Cr, Mn, Fe) alloys. Later, quasicrystals with eightfold, tenfold, and twelvefold rotation symmetries were also reported. A twelvefold symmetry has been found in a Ni-70.6 at%Cr alloy and an eightfold symmetry has been found in a Cr-Ni-Si alloy. This indicates a potential for nickel-chromium alloys to form the quasicrystal phase.An intermediate state between crystalline and quasicrystalline states is also discussed by Li, Teng, et. al. in an Al-Cu-Mg alloy due to the coexistence of micro-quasicrystal and micro-crystal grains. When regions larger than 1 nm are measured, a coherent boundary is found between micro-quasicrystal and micro-crystal grains.A diffraction pattern with seemingly twelvefold symmetry is found in pure nickel and Ni-20at%Cr sphere of about 25 nm diameter as shown in Figure 1. The diffraction patterns do not have true twelvefold symmetry but the first diffraction ring is found to have twelve diffracted spots. Similar structures are found in Ni-10at%Cr and shown in Figure 2 with a series of diffraction patterns.

AMETEK 820 ALLOY

Alloy Digest ◽  
1999 ◽  
Vol 48 (3) ◽  
Keyword(s):  
Physical Properties ◽  
Production Process ◽  
Tensile Properties ◽  
Powder Metal ◽  
Nickel Chromium ◽  
Chromium Alloys ◽  
Metal Products ◽  
Specialty Metal

Abstract AMETEK 820 alloy is a powder metallurgically produced strip that is used in hardfacing weld wire. The production process, however, can produce other special strip compositions such as the nickel-chromium alloys used as resistance alloys. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on powder metal forms. Filing Code: Ni-549. Producer or source: AMETEK Specialty Metal Products.

Oxide Film on Nickel-Chromium Alloys - Crystal Structure Studies

1953 ◽  
Vol 45 (8) ◽  
pp. 1734-1744 ◽  
Author(s):  
Earl A. Gulbransen ◽  
William R. McMillan
Keyword(s):  
Crystal Structure ◽  
Oxide Film ◽  
Nickel Chromium ◽  
Chromium Alloys

scholarly journals Effect of recasting on the elastic modulus of metal-ceramic systems from nickel-chromium and cobalt-chromium alloys

2007 ◽  
Vol 64 (7) ◽  
pp. 469-473 ◽  
Author(s):  
Nemanja Mirkovic
Keyword(s):  
Elastic Modulus ◽  
Testing Machine ◽  
Fracture Load ◽  
Bending Test ◽  
Chromium Alloy ◽  
Cobalt Chromium ◽  
Nickel Chromium ◽  
Ceramic Samples ◽  
Chromium Alloys ◽  
Metal Ceramic

Background/Aim. Elastic modulus of metal-ceramic systems determines their flexural strength and prevents damages on ceramics during mastication. Recycling of basic alloys is often a clinical practice, despite the possible effects on the quality of the future metal-ceramic dentures. This research was done to establish recasting effects of nickel-chromium and cobalt-chromium alloys on the elastic modulus of metalceramic systems in making fixed partial dentures. Methods. The research was performed as an experimental study. Six metal-ceramic samples of nickel-chromium alloy (Wiron 99) and cobalt-chromium alloy (Wirobond C) were made. Alloy residues were recycled through twelve casting generations with the addition of 50% of new alloy on the occasion of every recasting. Three- point bending test was used to determine elastic modulus, recommended by the standard ISO 9693:1999. Fracture load for damaging ceramic layer was recorded on the universal testing machine (Zwick, type 1464), with the speed of 0,05 mm/min. Results. The results of this research revealed significant differences between elasticity modules of metal-ceramic samples in every examined recycle generation. Recasting had negative effect on the elastic modulus of the examined alloys. This research showed the slight linear reduction of elastic modulus up to the 6th generation of recycling. After the 6th recycling there was a sudden fall of elastic modulus. Conclusion. Recasting of nickelchromium and cobalt-chromium alloys is not recommended because of the reduced elastic modulus of these alloys. Instead of reusing previously recasted alloys, the alloy residues should be returned to the manufacturer. .

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