Functionally Graded Al Alloy Matrix In-Situ Composites

2009 ◽  
Vol 41 (1) ◽  
pp. 242-254 ◽  
Author(s):  
S. Kumar ◽  
V. Subramaniya Sarma ◽  
B.S. Murty
Keyword(s):  
Functionally Graded ◽  
Al Alloy ◽  
Alloy Matrix ◽  
In Situ Composites

Filler Dispersion and Unidirectional Sliding Characteristics of As-Cast and Multi-Pass Friction Stir Processed ZrB2/AA7075 In-Situ Composites

2020 ◽  
Vol 143 (8) ◽  
Author(s):  
Rabindra Prasad ◽  
Harikishor Kumar ◽  
Parshant Kumar ◽  
S. P. Tewari ◽  
J. K. Singh
Keyword(s):  
Wear Rate ◽  
Friction Stir Processing ◽  
Tribological Behavior ◽  
Al Alloy ◽  
Scanning Electron Micrographs ◽  
Alloy Matrix ◽  
In Situ Composites ◽  
Friction Stir ◽  
Filler Dispersion

Abstract Despite the fabrication of particulate-reinforced composites via friction stir processing (FSP), an attempt was made to utilize FSP for the homogenization of filler dispersion in ZrB2/AA7075 in-situ composites fabricated via stir casting route, with varying weight percentages of ZrB2. The friction stir processing was performed for up to three passes with 100% overlap. The as-cast and friction stir processed (FSPed) composites were characterized for their microstructural, microhardness, and tribological behavior. The microstructural features revealed the increase in the misorientation angle among grain boundaries, with an increase in ZrB2 content and a number of FSP passes. Furthermore, the homogeneity of ZrB2 particles in the Al alloy matrix was significantly influenced by the number of FSP passes, which was quantified by Lorenz curves and Gini Indices. The FSPed alloy and composites exhibited higher microhardness as compared to their un-processed counterparts. The tribological behavior was investigated for three different load levels, i.e., 15 N, 30 N, and 45 N. The slope of the wear-rate at 45 N revealed that the Al-alloy exhibited a considerable increase in wear severity, whereas as-cast and FSPed composites did not show a significant increase. Both wear-rate and coefficient of friction decreased with an increase in the number of FSP passes and ZrB2 content. The scanning electron micrographs of worn surfaces confirmed the reduction in adhesion, abrasion, and delamination with the number of FSP passes. However, the synergism among the three depicted the overall tribological behavior.

scholarly journals Mechanical Properties of Al Matrix Composite Enhanced by In Situ Formed SiC, MgAl2O4, and MgO via Casting Process

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1767
Author(s):  
Yuhong Jiao ◽  
Jianfeng Zhu ◽  
Xuelin Li ◽  
Chunjie Shi ◽  
Bo Lu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Matrix Composite ◽  
Compression Strength ◽  
Casting Process ◽  
Al Alloy ◽  
Pyrolysis Process ◽  
Alloy Matrix ◽  
Al Matrix Composite ◽  
Al Matrix

Al matrix composite, reinforced with the in situ synthesized 3C–SiC, MgAl2O4, and MgO grains, was produced via the casting process using phenolic resin pyrolysis products in flash mode. The contents and microstructure of the composites’ fracture characteristics were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Mechanical properties were tested by universal testing machine. Owing to the strong propulsion formed in turbulent flow in the pyrolysis process, nano-ceramic grains were formed in the resin pyrolysis process and simultaneously were homogeneously scattered in the alloy matrix. Thermodynamic calculation supported that the gas products, as carbon and oxygen sources, had a different chemical activity on in situ growth. In addition, ceramic (3C–SiC, MgAl2O4, and MgO) grains have discrepant contents. Resin pyrolysis in the molten alloy decreased oxide slag but increased pores in the alloy matrix. Tensile strength (142.6 ± 3.5 MPa) had no change due to the cooperative action of increased pores and fine grains; the bending and compression strength was increasing under increased contents of ceramic grains; the maximum bending strength was 378.2 MPa in 1.5% resin-added samples; and the maximum compression strength was 299.4 MPa. Lath-shaped Si was the primary effect factor of mechanical properties. The failure mechanism was controlled by transcrystalline rupture mechanism. We explain that the effects of the ceramic grains formed in the hot process at the condition of the resin exist in mold or other accessory materials. Meanwhile, a novel ceramic-reinforced Al matrix was provided. The organic gas was an excellent source of carbon, nitrogen, and oxygen to in situ ceramic grains in Al alloy.

Processing of Primary Silicon and Mg2Si Reinforced Hybrid Functionally Graded Aluminum Composites by Centrifugal Casting

2012 ◽  
Vol 710 ◽  
pp. 395-400 ◽  
Author(s):  
S. Raghunandan ◽  
Jasim Akber Hyder ◽  
T.P.D. Rajan ◽  
K. Narayan Prabhu ◽  
B.C. Pai
Keyword(s):  
Centrifugal Casting ◽  
Casting Process ◽  
Primary Silicon ◽  
Shrinkage Porosity ◽  
Functionally Graded ◽  
Al Alloy ◽  
Primary Si ◽  
The Difference ◽  
Silicon Particles

In the present investigation, FGMs of mono-dispersed in-situ primary Si and their hybrids with Mg2Si reinforcements have been fabricated by the centrifugal casting process using 390 commercial Al alloy. Hard primary silicon particles are formed during the solidification of the 390 alloy and Mg2Si reinforcements are formed by the addition of varying amount of magnesium into the A390 aluminium alloy. Owing to the difference in density both primary silicon and Mg2Si gets segregated towards the inner periphery during centrifugal casting. The size of the Mg2Siin-situreinforcement phase is relatively smaller and is distributed in the edges of primary silicon particles and also individually in the matrix. Thein-situMg2Si and primary silicon can significantly increase the hardness and strength of the inner periphery of the casting. Higher Mg contents have been observed to introduce significant porosity leading to poor castings. Addition of phosphorous to the melt has led to the modification and refinement of primary Si morphology and also helped in the reduction of shrinkage porosity. Maximum hardness of 167 BHN is observed towards the inner periphery of the 390Al-2.5%Mg added in-situ composite.

Characterization of Damage Evolution in SiC Particle Reinforced Al Alloy Matrix Composites by In-Situ X-Ray Synchrotron Tomography

2011 ◽  
Vol 42 (10) ◽  
pp. 2999-3005 ◽  
Author(s):  
J. J. Williams ◽  
N. C. Chapman ◽  
V. Jakkali ◽  
V. A. Tanna ◽  
N. Chawla ◽  
...  
Keyword(s):  
Damage Evolution ◽  
Al Alloy ◽  
Matrix Composites ◽  
Alloy Matrix ◽  
X Ray ◽  
Synchrotron Tomography ◽  
Sic Particle

scholarly journals Fatigue crack growth in SiC particle reinforced Al alloy matrix composites at high and low R-ratios by in situ X-ray synchrotron tomography

2014 ◽  
Vol 68 ◽  
pp. 136-143 ◽  
Author(s):  
Peter Hruby ◽  
Sudhanshu S. Singh ◽  
Jason J. Williams ◽  
Xianghui Xiao ◽  
Francesco De Carlo ◽  
...  
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Al Alloy ◽  
Matrix Composites ◽  
Alloy Matrix ◽  
X Ray ◽  
Synchrotron Tomography ◽  
Sic Particle

The Constitutive Model and Processing Map for In Situ 5wt% TiB2 Reinforced 7050 Al Alloy Matrix Composite

2013 ◽  
Vol 575-576 ◽  
pp. 11-19 ◽  
Author(s):  
Ming Liang Wang ◽  
Zhe Chen ◽  
Dong Chen ◽  
Yi Wu ◽  
Xian Feng Li ◽  
...  
Keyword(s):  
Flow Stress ◽  
Constitutive Equation ◽  
Constitutive Model ◽  
Strain Rate ◽  
Matrix Composite ◽  
Processing Map ◽  
Al Alloy ◽  
Hot Workability ◽  
Alloy Matrix

This study investigated the constitutive flow behavior and hot workability of in-situ 5wt% TiB2 reinforced 7050 Al alloy matrix composite by hot compression experiments. Based on the experimental results of flow curves, a constitutive model describing the relationship of the flow stress, true strain, strain rate and temperature is proposed. Substantially, it is found the constitutive equation of flow stress is dependent on the strain, strain rate and temperature. The coefficients (E.g., α, n, Q and lnA) in the equation are functions of true strains. The results of the calculated values from constitutive equation are verified to well agree with the experimental values. Furthermore, the processing map of the composite is created in order to determine the hot processing domains. The optimum zones for hot workability and instability regions are identified. In instability domain, the microstructures display the main failure modes as the particle cracking and interface debonding.

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