In Situ Combustion Synthesis of Ti-Al Intermetallic Compounds in Al Alloy Casting Process

2007 ◽  
pp. 527-530
Author(s):  
Gue Serb Cho ◽  
Kang Rae Lee ◽  
Kyeong Hwan Choe ◽  
Kyong Whoan Lee
Keyword(s):  
Combustion Synthesis ◽  
Intermetallic Compounds ◽  
Casting Process ◽  
Al Alloy ◽  
In Situ Combustion ◽  
Alloy Casting

In Situ Combustion Synthesis of Ti-Al Intermetallic Compounds in Al Alloy Casting Process

2007 ◽  
Vol 26-28 ◽  
pp. 527-530
Author(s):  
Gue Serb Cho ◽  
Kang Rae Lee ◽  
Kyeong Hwan Choe ◽  
Kyong Whoan Lee
Keyword(s):  
Combustion Synthesis ◽  
Intermetallic Compounds ◽  
Titanium Aluminides ◽  
Intermetallic Phase ◽  
Al Alloy ◽  
Heat Of Reaction ◽  
Mixing Ratio ◽  
In Situ Combustion ◽  
X Ray

Ti-Al intermetallic compounds are regarded as promising materials for the hightemperature structural and coating applications. We focused on the joining of Al casting alloy with Ti-Al intermetallic compounds by in-situ combustion synthesis to improve the surface properties of Al casting components. Microstructures and phase formation behavior of Ti-Al based intermetallic compounds synthesized by combustion reaction were analyzed using scanning electron microscope(SEM) equipped with energy dispersive x-ray spectroscopy (EDS) and x-ray diffractometer(XRD) in Ti-Al intermetallic compounds. Three kinds of titanium aluminides of Ti3Al, TiAl and TiAl3 were synthesized by the heat from the Al molten metal and a coating layer of intermetallic phase were formed simultaneously on solidifed Al alloy surface. The shapes and microstructures of reacted compacts were varied by mixing ratio of elemental powders. The TiAl3 intermetallic compound was observed in the compacts regardless of the mixing ratio of elemental powders. And the unreacted Ti powders were remained in the reacted compacts due to the big size of Ti powder and low exothermic heat of reaction between Ti and Al powders. The zone that poured Al alloy diffused into the reacted Ti-25at.%Al compact of about 200 μm thickness was formed at the interface by the reaction between liquid molten Al alloy and solid Ti powders in green compact.

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.

Dry Sliding Wear Performance of Ni–SiC Composites Developed Through an In Situ Microwave Casting Process

2020 ◽  
Vol 142 (10) ◽  
Author(s):  
Satnam Singh ◽  
Dheeraj Gupta ◽  
Sarbjeet Kaushal
Keyword(s):  
Intermetallic Compounds ◽  
Sliding Wear ◽  
Volume Fraction ◽  
Casting Process ◽  
Dry Sliding Wear ◽  
Dry Sliding ◽  
Sliding Velocity ◽  
Uniform Dispersion ◽  
Sic Reinforcement

Abstract Metal matrix composites of nickel-based powder reinforced with silicon carbide are processed through a domestic microwave applicator. In situ melting and casting of composites were carried out using microwave energy with average processing time of 25 min. Phase analysis of processed composites revealed the formation of some hard-intermetallic compounds such as nickel silicides (NiSi, Ni2Si, and Ni3Si2) and carbides (Cr3C2 and Cr7C3). Microstructure analysis confirms the favorable growth of equiaxed grains with uniform dispersion of reinforcement and low porosity defects (1.5–1.8%). The formation of hard-intermetallic compounds and the presence of SiC reinforcement led to the increased microhardness of composites. Sliding wear tests under dry sliding conditions with varying load and velocity conditions revealed the formation of stable oxide tribolayers at 1.0 m/s of sliding velocity and 15 N load. Fractography of worn-out samples revealed abrasion of surfaces at the lower load (10 N) condition. However, on increasing the load, the shearing of surfaces due to adhesion, plastic deformations, and surface pullout was observed. At higher loads (20 N) and higher sliding velocities (1.5 m/s), particle pullout and three-body abrasive wear mechanisms were observed. The overall weight loss study revealed that the addition of 5% and 10% volume fraction of SiC reinforcement reduced the wear-rate by 58.9% and 80.6% in comparison to the pure nickel casting at the sliding velocity of 1 m/s and under 15 N load.

In Situ Combustion Synthesis of Composite Ceramics

1998 ◽  
Vol 159-160 ◽  
pp. 373-378 ◽  
Author(s):  
Wen Bin Cao ◽  
Jiang Tao Li ◽  
Ke Xin Chen ◽  
Y.L. Xia ◽  
Chang Chun Ge
Keyword(s):  
Combustion Synthesis ◽  
Composite Ceramics ◽  
In Situ Combustion

In Situ Combustion Synthesis of h-BN-SiC High-Temperature Ceramics

2007 ◽  
Vol 353-358 ◽  
pp. 1501-1504 ◽  
Author(s):  
Hong Bo Li ◽  
Yong Ting Zheng ◽  
Jie Cai Han
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Combustion Synthesis ◽  
Bending Strength ◽  
Silicon Powder ◽  
Nitrogen Pressure ◽  
In Situ Combustion ◽  
Reaction Thermodynamics ◽  
Adiabatic Combustion Temperature

The feasibility of fabricating h-BN-SiC high-temperature ceramics by in-situ combustion synthesis was demonstrated by igniting the mixture of boron carbide and silicon powder under 100MPa nitrogen pressure. The reaction thermodynamics and the adiabatic combustion temperature were calculated theoretically. The phase composition, microstructure and mechanical properties of composite were identified by XRD and SEM. The maximum bending strength and fracture toughness of the composite were 65.2 MPa and 1.4 MPa·m1/2 under room temperature, respectively. The effects of h-BN and SiC dilution contents on the mechanical properties of composite were also discussed.

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