A Study on Mechanical Properties and Strengthening Mechanisms of AA5052/ZrB2 In Situ Composites

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
Narendra Kumar ◽  
Gaurav Gautam ◽  
Rakesh Kumar Gautam ◽  
Anita Mohan ◽  
Sunil Mohan
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
High Strength ◽  
Strengthening Mechanism ◽  
Strengthening Mechanisms ◽  
In Situ Composites ◽  
Solid Solution Strengthening ◽  
Theoretical Yield ◽  
The Matrix

In the present study, in situ reaction technique has been employed to prepare AA5052 matrix composites reinforced with different vol. % of ZrB2 particles (i.e., 0, 4.5, and 9 vol. %). Composites have been characterized by X-ray diffraction (XRD) to confirm the in situ formation of ZrB2 particles in the matrix. Optical Microscopy (OM) studies reveal the refinement of aluminum-rich phase due to the presence of ZrB2 particles. Scanning electron microscopy (SEM) studies reveal size and distribution of ZrB2 particles while transmission electron microscopy (TEM) reveals the presence of dislocations in the matrix around ZrB2 particles. Hardness and tensile testing of composites have been carried out at room temperature to evaluate the mechanical properties. The results reveal the improvement in hardness and strength with increased amount of ZrB2 particles. Strength of AA5052/ZrB2 in situ composites has been analyzed by various strengthening mechanism models. The analysis revealed that Orowan and Solid solution strengthening mechanisms are the predominant mechanism for high strength composites. Theoretical yield strength is about 6–10% higher than the experimental values due to clustering tendency of ZrB2 particles.

scholarly journals Microstructure and Strengthening Model of Cu–Fe In-Situ Composites

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3464
Author(s):  
Keming Liu ◽  
Xiaochun Sheng ◽  
Qingpeng Li ◽  
Mengcheng Zhang ◽  
Ningle Han ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Cold Deformation ◽  
Strengthening Mechanism ◽  
Strengthening Mechanisms ◽  
Petch Relation ◽  
In Situ Composites ◽  
Deformation Strain ◽  
Strength Evolution ◽  
The Matrix

The tensile strength evolution and strengthening mechanism of Cu–Fe in-situ composites were investigated using both experiments and theoretical analysis. Experimentally, the tensile strength evolution of the in-situ composites with a cold deformation strain was studied using the model alloys Cu–11Fe, Cu–14Fe, and Cu–17Fe, and the effect of the strain on the matrix of the in-situ composites was studied using the model alloys Cu–3Fe and Cu–4.3Fe. The tensile strength was related to the microstructure and to the theoretical strengthening mechanisms. Based on these experimental data and theoretical insights, a mathematical model was established for the dependence of the tensile strength on the cold deformation strain. For low cold deformation strains, the strengthening mechanism was mainly work hardening, solid solution, and precipitation strengthening. Tensile strength can be estimated using an improved rule of mixtures. For high cold deformation strains, the strengthening mechanism was mainly filament strengthening. Tensile strength can be estimated using an improved Hall–Petch relation.

scholarly journals TEM observation of precipitates and their role to mechanical properties in Ti-5553 alloy heated to some temperatures up to 923 K

2020 ◽  
Vol 321 ◽  
pp. 11035
Author(s):  
E. Sukedai ◽  
E. Aeby-Gautier ◽  
M. Dehmas
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Hardening Mechanism ◽  
Transmission Electron ◽  
The Matrix ◽  
Higher Temperature ◽  
Shearing Mechanism ◽  
Hardness Values ◽  
Measured Hardness

A Ti-5553 specimen was continuously heated to 923 K and simultaneously in-situ HEXRD profiles were taken. In addition, specimens heated at the same rate to several temperatures up to 923 K and further quenched were observed by transmission electron microscopy. Based on both results obtained, transformation sequence was clarified, precipitations of ω-, α”iso- and α-phases were confirmed, and size and density of these precipitates were measured. Hardness values of those specimens were also measured. The hardening mechanism was considered as shearing-mechanism for specimens aged at lower temperatures and by-pass one for specimens aged at higher temperature. An attempt of distinction between α”iso - and α-precipitates was also tried. Both precipitates were in needle-like shape and a possibility was suggested by measuring angles between two needle-shape precipitates on {110} of the matrix and comparing with each other.

In Situ Decomposition of Silicon Nitride Particles in Titanium Composite and its Mechanical Properties

2017 ◽  
Vol 737 ◽  
pp. 38-43
Author(s):  
Hisashi Imai ◽  
Hiroyasu Yamabe ◽  
Katsuyoshi Kondoh ◽  
Junko Umeda ◽  
Anak Khantachawana
Keyword(s):  
Mechanical Properties ◽  
Silicon Nitride ◽  
Solid Phase ◽  
High Strength ◽  
Solid Solution Strengthening ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Solution Strengthening ◽  
Ti Powder

Dependence of the mechanical properties of PM extruded titanium with the silicon nitride (Si3N4) on solid phase decomposition of Si3N4 was investigated. Si3N4 particles within Ti composite powder were decomposed during spark plasma sintering at 1223 K with 30 MPa pressure for 3.6 ks; and then, decomposition by-products of nitrogen and silicon atoms were defused into titanium matrix. The extruded Ti-1.0 mass% Si3N4 composite showed ultimate tensile strength (UTS) of 1139 MPa, and yield stress (0.2%YS) of 1065 MPa. UTS and 0.2%YS of P/M extruded Ti-1.0 mass% Si3N4 composite were 2 and 2.5 times compared to extruded pure Ti powder material, respectively. It was considered that the solid solution strengthening of both nitrogen and silicon originated from Si3N4 caused the high strength of PM extruded Ti-1.0 mass% Si3N4 composite.

Influence of Cr2O3 Addition on the Properties of TiAl Composites

2011 ◽  
Vol 230-232 ◽  
pp. 789-792
Author(s):  
Jian Feng Zhu ◽  
Wen Wen Yang ◽  
Fang Ni Du
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Synthesis Method ◽  
Strengthening Mechanism ◽  
Reaction Synthesis ◽  
The Matrix ◽  
Method Effects ◽  
Particulate Reinforced

Using Ti, Al and Cr2O3 as starting materials, Al2O3 particulate reinforced TiAl composites have been fabricated by in-situ reaction synthesis method. Effects of the Cr2O3 addition on the microstructures and mechanical properties of the TiAl/Al2O3 composites were investigated in detail. The results show that the composites have a matrix of TiAl, Ti3Al, and minor Cr containing phases, and a second reinforcement Al2O3. The addition of Cr2O3 effectively refined the structure of the matrix, and as a result, the mechanical properties of TiAl composites are improved. At Cr2O3 7.36 wt%, the flexural strength and fracture toughness reach the maximum values of 634.62 MPa and 9.79 MPa·m1/2, which are increased by 80% and 30%, respectively. The strengthening mechanism is also discussed.

scholarly journals Mechanical properties and microstructure of Al2O3/TiAl in situ composites doped with Cr and V2O5

2012 ◽  
Vol 44 (1) ◽  
pp. 73-80 ◽  
Author(s):  
Kun Zhang ◽  
Wang Fen ◽  
Jianfeng Zhu ◽  
Huae Wu
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Phase Composition ◽  
Flexural Strength ◽  
Strengthening Mechanism ◽  
Al2o3 Content ◽  
In Situ Composites ◽  
Al2o3 Ceramic ◽  
In Situ Composite

Al2O3/TiAl in situ composites doped with Cr and V2O5 were successfully prepared from Ti, Al, TiO2, Cr and V2O5 by hot pressing. The effect of in situ formed Al2O3 content on the phase composition, microstructure and mechanical properties of Al2O3/TiAl composites were investigated. The results show that the as-synthesized composites mainly consisted of ?-TiAl/?2-Ti3Al matrix and dispersive Al2O3 reinforcing phases. The in situ formed fine Al2O3 ceramic particles mainly disperse on the grain boundaries of TiAl, resulting in refinement of TiAl matrix, which improves the mechanical properties of the Al2O3/TiAl in situ composite. The composite with 7.54 at.% Al2O3 possesses the maximum flexural strength and fracture toughness of 335.38 MPa and 5.39 MPa m1/2, respectively. The strengthening mechanism was also discussed in detail.

Microstructure and Mechanical Properties of Al2O3-TiC/Al in Situ Composites

2006 ◽  
Vol 326-328 ◽  
pp. 1857-1860
Author(s):  
Hong Mei Chen ◽  
Hua Shun Yu ◽  
Jing Zhang ◽  
Lin Zhang ◽  
Guang Hui Min
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Room Temperature ◽  
Volume Fraction ◽  
Matrix Alloy ◽  
Co2 Gas ◽  
In Situ Composites ◽  
In Situ Reaction ◽  
The Matrix

The Al2O3-TiC/Al composites were prepared by injecting CO2 gas into Ti contained Al-Si alloy melts. The microstructure of the composites was examined by XRD, SEM and TEM. It was indicated that both Al2O3 and TiC particles can be formed by the in situ reaction of CO2 with Ti and Al in the melten alloys. The Al2O3 and TiC particles in size of 0.3~1.5μm distributed uniformly in the matrix. The volume fraction of the particles is mainly depend upon the time of CO2 injection.The tensile strength at room temperature of the composites can reach 346.08MPa and the hardness is 149.6MPa HBS, repectively, which are higher than those of the matrix alloy.

Microstructure and Strengthening Mechanism of TiCp/ZA-12 Composites

2007 ◽  
Vol 348-349 ◽  
pp. 221-224 ◽  
Author(s):  
Wang Xiang ◽  
Guo Bing Ying
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Interface Reaction ◽  
Matrix Alloy ◽  
Strengthening Mechanism ◽  
Strengthening Mechanisms ◽  
Dispersion Strengthening ◽  
Transmission Electron ◽  
Scanning Electron

TiCp/ZA-12 composites have been fabricated by XDTM method and stirring-casting techniques. Microstructure of the composites has been studied by means of scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that TiC particles distribute uniformly in ZA-12 matrix alloy. The interface between reinforcements and matrix alloy is very clean, and there is not interface reaction between TiC particles and ZA-12 matrix alloy. The tests for mechanical properties reveal that the tensile strength, yield strength, elastic modulus and hardness of the composites are improved obviously due to the incorporation of TiC particles. The strengthening mechanisms are attributed to the following factors: dispersion strengthening of TiC particles, grain refinement of ZA-12 matrix alloy and high-density dislocations existing in ZA-12 alloy.

Microstructure and Mechanical Properties of AIN Particles Reinforced Magnesium Matrix Composites with In Situ Synthesis Process

2016 ◽  
Vol 256 ◽  
pp. 181-185
Author(s):  
Zhao Hui Wang ◽  
Bo Li ◽  
Xian Du ◽  
Ke Liu ◽  
Shu Bo Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Microstructural Analysis ◽  
Matrix Alloy ◽  
Strengthening Mechanism ◽  
Synthesis Process ◽  
Matrix Composites ◽  
Magnesium Matrix ◽  
Magnesium Matrix Composites ◽  
The Matrix

In this paper, In Situ AlN particles reinforced magnesium matrix composites were fabricated. The results show that the AlN phases can be In Situ synthesized in AZ91D alloy with the addition of Mg3N2. The microstructure and phases of the matrix alloys and the composites were investigated by OM, SEM and XRD. The hardness and mechanical properties of the matrix alloys and the composites were also obtained. Compared with those of the matrix alloy, the grains of composites were refined obviously and the mechanical properties of composites were improved significantly. The microstructural analysis indicates that the AlN particles can act as the heterogeneous nucleation of α-Mg phases in the composites. The strengthening mechanism of the composites with AlN particles was discussed.

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