Displacement Reactions in the Ni-Al-O System Resulting in Periodic Layer Structures

1994 ◽  
Vol 365 ◽  
Author(s):  
Daniel W. Song ◽  
Ramesh Subramanian ◽  
RÜdiger Dieckmann
Keyword(s):  
Reaction Mechanism ◽  
Periodic Structures ◽  
Ceramic Composites ◽  
Processing Technologies ◽  
Layer Structures ◽  
Metal Ceramic ◽  
Displacement Reactions ◽  
Periodic Layer ◽  
In Situ Processing

ABSTRACTDisplacement reactions may play an important role in in situ processing technologies for the production of metal-ceramic composites. To better understand such reactions displacement reactions between NiO and Al were studied at high temperatures. Different reaction layers with periodic structures were observed involving Al2O3, Al3Ni, Al3Ni2, Ni and Al. The experimental observations are presented and discussed with regard to the reaction mechanism.

scholarly journals Preparation of metal–ceramic composites by sonochemical synthesis of metallic nano-particles and in-situ decoration on ceramic powders

2016 ◽  
Vol 31 ◽  
pp. 417-422 ◽  
Author(s):  
A. Poulia ◽  
P.M. Sakkas ◽  
D.G. Kanellopoulou ◽  
G. Sourkouni ◽  
C. Legros ◽  
...  
Keyword(s):  
Ceramic Composites ◽  
Nano Particles ◽  
Ceramic Powders ◽  
Sonochemical Synthesis ◽  
Metal Ceramic

Partial Reduction of NiAl2O4 - Mechanism and the Influence of Doping

1995 ◽  
Vol 398 ◽  
Author(s):  
Z. Zhang ◽  
E. Üstündag ◽  
S.L. Sass
Keyword(s):  
Reaction Mechanism ◽  
Intermediate Stage ◽  
Reduction Reaction ◽  
Reduction Mechanism ◽  
Partial Reduction ◽  
Metal Ceramic ◽  
Mechanism And Kinetics ◽  
Equilibrium Phases ◽  
Metastable Defect

ABSTRACTMetal-ceramic microstructures were formed in situ by partial reduction of the spinel compound NiAl2O4. At 1300°C the reduction reaction passed through an intermediate stage involving the formation of Ni and metastable “defect spinel” phases, before the appearance of the equilibrium phases, Ni + α-Al2O3. At 1100°C, depending on the reduction time, the products of the reduction reaction were Ni and the metastable “defect spinel” for less than 24 hours; Ni + θ-Αl2Ο3 for 24-48 hours; and Ni + GI-AI2O3 for 144-168 hours. The effects of dopants, such as Cr2O3, MgO, TiO2 and Y2O3, on the reduction mechanism and kinetics were examined and shown, in the case of TiO2, to have a controlling influence. A reduction reaction mechanism is proposed.

In-Situ Processing of Mosi2-Base Composites

1993 ◽  
Vol 322 ◽  
Author(s):  
N. Patibandla ◽  
W.B. Hillig ◽  
M.R. Ramakrishnan ◽  
D.E. Alman ◽  
N.S. Stoloff
Keyword(s):  
Chemical Vapor ◽  
Chemical Vapor Infiltration ◽  
Ceramic Fibers ◽  
Advantages And Disadvantages ◽  
Powder Sintering ◽  
Displacement Reactions ◽  
In Situ Processing ◽  
Reactive Powder ◽  
Vapor Infiltration

AbstractThree different methods of preparing Mosi2 and composites reinforced with ceramic fibers by reactive in-situ processing are described. Reactive powder sintering (co-synthesis) of elemental powders, chemical vapor infiltration/deposition and reactive vapor infiltration are examined. Monolithic Mosi2, SiC particle-reinforced Mosi2 or fibrous Mosi2 composites reinforced with Nicalon fiber were prepared. The advantages and disadvantages of these processes relative to more traditional processing techniques such as HIPing of prealloyed powders, mechanical alloying and a reported in-situ displacement reactions are discussed.

Crack Growth in Metal-Ceramic Composites

2000 ◽  
Author(s):  
Parul Agrawal ◽  
C. T. Sun
Keyword(s):  
Residual Stresses ◽  
Crack Growth ◽  
Crack Path ◽  
Ceramic Composites ◽  
Fracture Mechanisms ◽  
Environmental Scanning ◽  
Metal Ceramic ◽  
Bend Tests ◽  
Point Bend

Abstract This research focuses on the fracture mechanisms in various metal-ceramic composites. The objective was to study the effects of volume fractions, residual stresses and other microstructural features like particle size and contiguity of the constituent phases, on fracture. Neutron diffraction tests were performed to measure residual stresses in these composites. In-situ 3-point bend tests were performed inside the ESEM (Environmental scanning electron microscope) chamber to observe crack growth. It was found that residual stresses and contiguity play dominant roles in fracture and defining the crack path. The correlations between residual stresses and other microstructural features with the crack path and failure mechanisms were established based on experimental observations.

Metal-ceramic composites via in-situ methods

1997 ◽  
Vol 68 (2) ◽  
pp. 132-155 ◽  
Author(s):  
B.S.S. Daniel ◽  
V.S.R. Murthy ◽  
G.S. Murty
Keyword(s):  
Ceramic Composites ◽  
Metal Ceramic ◽  
In Situ Methods

In Situ Processing of Silicon Carbide Layer Structures

1995 ◽  
Vol 78 (11) ◽  
pp. 3160-3162 ◽  
Author(s):  
Nitin P. Padture ◽  
David C. Pender ◽  
Sataporn Wuttiphan ◽  
Brian R. Lawn
Keyword(s):  
Silicon Carbide ◽  
Carbide Layer ◽  
Layer Structures ◽  
In Situ Processing

Metal-Ceramic Composites Prepared through In Situ Decomposition of Transition Metal Nitrides

2007 ◽  
Vol 352 ◽  
pp. 125-128
Author(s):  
Xi Hai Jin ◽  
Lian Gao ◽  
Jing Sun
Keyword(s):  
Transition Metal ◽  
Ceramic Composites ◽  
Metal Particles ◽  
Metal Nitrides ◽  
Transition Metal Nitrides ◽  
Microstructure And Properties ◽  
Uniform Microstructure ◽  
Metal Ceramic ◽  
In Situ Decomposition

Co/ZnO and Ni/Al2O3 composites were prepared by in-situ decomposition of CoNx and NiNx during sintering, using CoNx/ZnO and NiNx/Al2O3 mixtures synthesized through an in-situ nitridation method as the starting powders. It was found that these composites showed a very uniform microstructure with metal particles homogeneously distributed among matrix grains. The microstructure and properties were tentatively studied.

In situ formation of metal-ceramic microstructures, including metal-ceramic composites, using reduction reactions

1993 ◽  
Vol 41 (7) ◽  
pp. 2153-2161 ◽  
Author(s):  
E. Ustundag ◽  
R. Subramanian ◽  
R. Vaia ◽  
R. Dieckmann ◽  
S.L. Sass
Keyword(s):  
Ceramic Composites ◽  
Reduction Reactions ◽  
Metal Ceramic ◽  
In Situ Formation
Sign in / Sign up

Export Citation Format

Share Document