In situ hot-stage TEM study of a diffusion-bonded Al/SiC interface

1992 ◽  
Vol 50 (1) ◽  
pp. 218-219
Author(s):  
P. L. Ratnaparkhi
Keyword(s):  
Interfacial Structure ◽  
Matrix Composites ◽  
Reactive Metal ◽  
The Past ◽  
Covalently Bonded ◽  
Metal Ceramic ◽  
Commercially Important ◽  
Ceramic Interfaces ◽  
Particulate Reinforced

Metal/ceramic interfaces have been of great scientific and technological interest for the past two decades. Most studies have been performed on commercially important ceramic-fibre and particulate-reinforced metal-matrix composites. In this investigation, the interfacial structure and chemistry at a diffusion bonded Al/SiC interface was examined at the atomic level in order to understand the fundamental principles that govern bond formation in the solid state between a low temperature non-reactive metal and a high-temperature covalently bonded ceramic.

Preparation and Microstructure of Nano ZrB2 Reinforced Aluminum Matrix Composites

2013 ◽  
Vol 575-576 ◽  
pp. 179-182
Author(s):  
Hong Ming Wang ◽  
Guirong Li ◽  
Yun Cai ◽  
Yu Tao Zhao
Keyword(s):  
Molten Aluminum ◽  
Aluminum Matrix ◽  
Aluminum Matrix Composites ◽  
Direct Reaction ◽  
Matrix Composites ◽  
Liquid Reaction ◽  
Particulate Reinforced ◽  
Electronic Microscope ◽  
Observation Results

The ZrB2 particulate reinforced aluminum matrix composites were fabricated via melt direct reaction method using Al-K2ZrF6-KBF4 components. 850°C and 30 min were the optimized synthesizing temperature and reaction time separately. The metallurgical thermodynamic and kinetic processes were then analyzed in detail. It reveals that the interphases include Al3Zr, AlB2, [Z and [ atoms. The ZrB2 particulates can be acquired through the molecular combination between Al3Zr and AlB2 or atomic combination between Zr and B atomics. The in situ reaction between reactive salts and molten aluminum takes place spontaneously, which exhibits the character of liquid-liquid reaction. Scanning electronic microscope observation results demonstrate that the sizes of ZrB2 particulates are almost 100-200 nm. The intervals between particles are almost 200-400 nm, demonstrating a unirom status of distribution.

Understanding Mechanical Integrity of Metal/Ceramic Interfaces Through In-Situ Micro Mechanical Testing and Multiscale Simulations

2018 ◽  
Author(s):  
Xiaoman Zhang ◽  
Yang Mu ◽  
Shuai Shao ◽  
Collin Wick ◽  
Ramu Ramachandran ◽  
...  
Keyword(s):  
Mechanical Testing ◽  
Density Functional ◽  
Ceramic Coating ◽  
Minimum Energy ◽  
Shear Loading ◽  
Interfacial Region ◽  
Loading Conditions ◽  
Metal Ceramic ◽  
Ceramic Interfaces

Mechanical failures of interfacial regions of ceramic-coating/metal-adhesion-layer/substrate systems were measured quantitatively and observed concurrently through instrumented microscale mechanical testing in-situ a scanning electron microscope (SEM). Failure of the interfacial regions of coating/interlayer/substrate systems was observed in micro-pillar specimens in-situ under different loading conditions, including shear, compression, and tension. Under shear loading, shear failure of the interfacial region was observed to occur in two stages: an initial uniform shear plastic deformation of the entire metal interlayer followed by an unstable shear-off close to the metal/ceramic interface. Additional testing under compression loading conditions suggests that the unstable shear-off is concomitant with the metal/ceramic interface going from being “locked”, with no relative displacement between materials on the two sides of the interface, to being “unlocked”, with significant relative displacements. Failure of the interfacial region was also observed under tensile loading conditions. Density functional theory (DFT) and molecular dynamics (MD) studies on one particular metal/ceramic interface, namely Ti/TiN, showed that a weak interaction plane exists in the metal layer near the chemical interface in a coherent Ti/TiN structure. Consequently, the free energy and theoretical shear strength of the semi-coherent Ti/TiN interface is found to depend on the physical location of the misfit dislocation network (MDN). The minimum energy and strength of the interface occur when the MDN is near, but not at the chemical interface. The present work gives new insight into the nature of mechanical failure of metal/ceramic interfaces, is relevant to materials-based engineering of metal/ceramic interfaces, and has applications to engineering of ceramic coating/substrate systems.

In Situ TiB2 Reinforced Al-12Si Alloy Composites by Semisolid Processing

2011 ◽  
Vol 675-677 ◽  
pp. 763-766 ◽  
Author(s):  
Zong Ning Chen ◽  
Tong Min Wang ◽  
Jun Xu ◽  
Jing Zhu ◽  
Hong Wang Fu ◽  
...  
Keyword(s):  
Synthesis Method ◽  
High Strength ◽  
Semisolid Slurry ◽  
Matrix Composites ◽  
Semisolid Processing ◽  
Eutectic Si ◽  
Average Size ◽  
Tib2 Particles ◽  
Particulate Reinforced

Employing a cooling slope technique to produce semisolid slurry, in-situ 3wt%TiB2 particulate reinforced Al-12Si alloy composites have been successfully fabricated by flux-assisted synthesis method. It has been shown that the minute TiB2 particles with size 200-500nm uniformly distribute in the spherical α-Al structure and at the boundary of the eutectic Si. Two groups of contrast experiments with and without flowing on the slope have been performed to investigate the influence of the semisolid processing on the microstructure of the composites. Results have shown that α-Al grain is rather spherical and with an average size of 47.4μm, which indicates semisolid processing can be a potential route to produce metal matrix composites with high strength and good ductility.

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