Mechanical Behavior of Reactively Hot-Pressed Aluminide Matrix Composites

1996 ◽  
Vol 460 ◽  
Author(s):  
M. Inoue ◽  
K. Suganuma ◽  
K. Niihara
Keyword(s):  
Fracture Toughness ◽  
Hot Pressing ◽  
Fine Particles ◽  
Relaxation Effect ◽  
Matrix Composites ◽  
Ambient Temperatures ◽  
Environmental Embrittlement ◽  
The Matrix ◽  
Al Matrix Composites ◽  
Al Matrix

ABSTRACTFeAl and Ni3Al matrix composites containing various fine particles were fabricated successfully by reactive hot-pressing. The strength and the fracture toughness of these composites at ambient temperatures were evaluated. The addition of β-SiC particles was effective for strengthening of the Fe-40at%Al matrix, however, an extreme decrease of fracture toughness occurred due to the suppression of stress relaxation effect by plastic deformation at a crack tip. The fracture toughness of the reactively hot pressed Fe-40at%Al and its composites was also affected by the environmental embrittlement effect. TiB2 and ZrB2 particles in the Fe-40at%Al matrix composites were clarified to play a role in the reduction of the environmental effect. For the Ni-25at%Al matrix, higher flexural strength was achieved by the addition of TiB2, TiC and TiN particles. TiB2 particles reacted with the matrix during hot-pressing. The Ni-25at%Al/TiB2 composite had a fracture strength of 1.5 GPa in spite of large grain size of the matrix. TiC and TiN were the best choices as effective reinforcing matrials for the Ni3Al matrix among the chemical compatible ones.

A Review on In Situ Synthesis of Al/TiC and Al/SiC-Composites

2016 ◽  
Vol 684 ◽  
pp. 287-292 ◽  
Author(s):  
Hrusikesh Nath
Keyword(s):  
Fine Particles ◽  
Matrix Composites ◽  
Homogeneous Microstructure ◽  
Large Particles ◽  
The Matrix ◽  
Matrix Reinforcement ◽  
Sic Composites ◽  
Al Matrix Composites ◽  
Al Matrix

The in-situ synthesis of ceramic particles in Al-matrix composites gives an uniform and homogeneous microstructure. The matrix reinforcement interface is compatible with the matrix, interface is clean and provides good interface bonding. The evenly distributed sub micron sized reinforcement particles in Al-matrix enhances the strength and toughness of the composite. The formation of particle clusters and agglomerations are minimized or eliminated by suitably choosing the in-situ process parameters. Large particles and agglomerate are easily fractured where as evenly distributed fine particles are resistant to crack propagation and improves the strength of the composites. The problem encountered with the formation of secondary intermetallic Al3Ti and Al4C3 phases are addressed.

scholarly journals Study on In-Situ Synthesis Process of Ti–Al Intermetallic Compound-Reinforced Al Matrix Composites

Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 1967
Author(s):  
Qiong Wan ◽  
Fuguo Li ◽  
Wenjing Wang ◽  
Junhua Hou ◽  
Wanyue Cui ◽  
...  
Keyword(s):  
Intermetallic Compound ◽  
Intermetallic Compounds ◽  
Hot Pressing ◽  
Milling Time ◽  
Holding Time ◽  
Matrix Composites ◽  
Al Matrix Composites ◽  
Hot Pressing Sintering ◽  
Al Matrix

In this study, ball-milled powder of Ti and Al was used to fabricate Ti–Al intermetallic compound-reinforced Al matrix composites by an in-situ reaction in cold-pressing sintering and hot-pressing sintering processes. The detailed microstructure of the Ti–Al intermetallic compound-reinforced Al composite was characterized by optical microscopy (OM), X-ray diffraction (XRD), energy dispersive spectrometry (EDS), and electron backscattered diffraction (EBSD). The results indicate that a typical core–shell-like structure forms in the reinforced particles. The shell is composed of a series of Ti–Al intermetallic compounds and has good bonding strength and compatibility with the Al matrix and Ti core. With cold-pressing sintering, the shell around the Ti core is closed, and the shell thickness increases as the milling time and holding time increase. With hot-pressing sintering, some radiating cracks emerge in the shell structure and provide paths for further diffusion of Ti and Al atoms. The Kirkendall effect, which is caused by the difference between the diffusion coefficients of Ti and Al, results in the formation of cavities and a reduction in density degree. When the quantity of the intermetallic compounds increases, the hardness of the composites increases and the plasticity decreases. Therefore, factors that affect the quantity of the reinforcements, such as the milling time and holding time, should be determined carefully to improve the comprehensive properties of the composites.

Investigation of NiAl–TiB2in situcomposites

1997 ◽  
Vol 12 (4) ◽  
pp. 1083-1090 ◽  
Author(s):  
J. T. Guo ◽  
Z. P. Xing
Keyword(s):  
Fracture Toughness ◽  
Yield Strength ◽  
Hot Pressing ◽  
Room Temperature ◽  
Tensile Yield Strength ◽  
Matrix Composites ◽  
Orientation Relationships ◽  
The Matrix ◽  
Atomically Flat ◽  
Nial Matrix

A hot-pressing aided exothermic synthesis (HPES) technique to fabricate NiAl matrix composites containing 0 and 20 vol.% TiB2 particles was developed. The conversion of mixtures of elements to the product was complete after processing, and TiB2 particles in the matrix were uniformly dispersed. The microstructure and interfaces were very thermally stable. The interfaces between NiAl and TiB2 were atomically flat, sharp, and generally free from interfacial phases. In some cases, however, thin amorphous layers existed at NiAl/TiB2 interfaces. At least three kinds of orientation relationships between TiB2 and NiAl were observed. The compressive yield strengths at room temperature and at 1000 °C of the composite were approximately three times as strong as those of the unreinforced NiAl. The tensile yield strength at 980 °C of the composite was about three times stronger than that of NiAl. The ambient fracture toughness of the composite was slightly greater than that of the monolithic NiAl.

Synthesis of Carbon Nanotube-Reinforced Al Matrix Composites

2007 ◽  
Vol 539-543 ◽  
pp. 860-865 ◽  
Author(s):  
Jung Ho Ahn ◽  
Yan Li Wang ◽  
Yong Jin Kim ◽  
Sung Jin Kim ◽  
Hyung Sik Chung
Keyword(s):  
Carbon Nanotube ◽  
Critical Factor ◽  
Control Agent ◽  
Matrix Composites ◽  
Process Control Agent ◽  
Composite Powders ◽  
Uniform Dispersion ◽  
The Matrix ◽  
Al Matrix Composites ◽  
Al Matrix

We have synthesized multi-wall carbon nanotube (MWCNT)-reinforced Al matrix composites. The Al/MWCNT composite powders were prepared by ball milling using pristine Al or ball-milled Al powders as starting materials. The composite powders were consolidated by a conventional cold-compaction, followed by sintering. Uniform dispersion of individual MWCNTs within the matrix was in particular a critical factor for obtaining high density and high quality Al/MWCNT composites. Compared to pristine Al powders as starting materials, the Al powders previously attrition-ball-milled with carbon-based PCA (process control agent) in an ammonia atmosphere resulted in a better distribution of carbon nanotubes within the Al matrix and a higher density after sintering.

scholarly journals Microstructure and properties of in situ Ti–Al intermetallic compound-reinforced Al matrix composites with dispersive distribution of core–shell-like structure

2021 ◽  
Vol 30 ◽  
pp. 263498332110061
Author(s):  
Qiong Wan ◽  
Fuguo Li ◽  
Wenjing Wang ◽  
Junhua Hou ◽  
Wanyue Cui ◽  
...  
Keyword(s):  
Intermetallic Compound ◽  
Hot Pressing ◽  
Compaction Pressure ◽  
Compressive Yield Strength ◽  
Core Shell ◽  
Matrix Composites ◽  
Al Matrix Composites ◽  
Hot Pressing Sintering ◽  
Al Matrix

Recently, Ti–Al intermetallic compound-reinforced Al matrix composites have attracted increasing attention because of their high specific modulus, strength, and thermal stability. In this study, blended powders of Ti and Al were ball milled and fabricated to in situ Ti–Al intermetallic compound-reinforced Al matrix composites by cold-pressing and hot-pressing sintering. The microstructures and component of core–shell-like structure in reinforcement were observed and analyzed. Material properties including hardness, density, and compression performance were tested and analyzed according to experimental processes. The results indicate that the time point of compression in hot-pressing sintering is crucial to obtain the closed core–shell-like structures. Based on the orthogonal experimental data, entropy methods and technique for order preference by similarity to ideal solution were combined to select the process parameters (ratio of Ti and Al, milling time, sintering temperature, holding time, and compaction pressure) for the best comprehensive performance of Vickers hardness and compressive yield strength.

scholarly journals Microstructure and mechanical properties of aluminum matrix composites with different volume fractions of surface-oxidized nanodiamonds

2020 ◽  
Vol 29 ◽  
pp. 2633366X2097749
Author(s):  
Wei Yan ◽  
Mingchen Ma ◽  
Heyi Kang ◽  
Qian Li ◽  
Hongqun Tang ◽  
...  
Keyword(s):  
Volume Fraction ◽  
Testing Machine ◽  
Aluminum Matrix ◽  
Surface Oxidation ◽  
Aluminum Matrix Composites ◽  
Matrix Composites ◽  
Vacuum Sintering ◽  
The Matrix ◽  
Al Matrix Composites ◽  
Al Matrix

Nanodiamonds (NDs) have the characteristics of both diamonds and nanomaterials. However, it is difficult to disperse NDs, and this is why there is less research regarding NDs in the field of aluminum matrix composites. In the present work, NDs were modified via surface oxidation, and ND/Al matrix composites were successfully prepared via mechanical ball milling and vacuum sintering. The effects of different volume fraction of NDs (1%, 3%, 5%, 7%) after surface oxidation on the ND/Al matrix composite were analyzed using a metallographic microscope, scanning electron microscope, infrared spectrometer, X-ray diffractometer, microhardness tester, and universal testing machine. The results show that the optimal temperature of surface oxidation treatment is 673 K, which effectively purifies the surface of ND and introduces appropriate C=O functional groups. NDs are uniformly distributed in the aluminum matrix, and no harmful Al4C3 phase is formed. With an increase in the volume fraction of NDs, the grain size of the matrix first decreases and then increases, and the ultimate compressive strength first increases and then decreases. The volume fraction of ND with better comprehensive performance is 3% and the yield strength increased by 19%.

Sign in / Sign up

Export Citation Format

Share Document