Microstructure and Mechanical Properties of Graded Materials Prepared by Field-Activated and Pressure-Assisted Combustion Synthesis

2008 ◽  
Vol 368-372 ◽  
pp. 1876-1878 ◽  
Author(s):  
Qing Sen Meng ◽  
Shao Ping Chen ◽  
Y.L. Shen ◽  
Cui Rong Liu ◽  
Z.A. Munir
Keyword(s):  
Combustion Synthesis ◽  
Mechanical Characterization ◽  
Gradient Material ◽  
Micro Hardness ◽  
Hot Press ◽  
Rockwell Hardness ◽  
Graded Materials ◽  
Gradient Materials ◽  
Better Than

Using the processes of field-activated and pressure-assisted combustion synthesis (FAPACS), FGM materials (FGMs) were prepared under the conditions of field-assisted and the hot-press. The microstructure and the phase composition of the interface of the graded materials were investigated and the results showed that the metallurgical joining layer was formed in the interfaces of the (TiB2)pNi/Ni3Al/405 steel. The mechanical characterization of the gradient materials showed that the composition and the micro-hardness of the gradient material were gradient distributed, and its surface Rockwell hardness and wear resistance are better than that of hardened 20Cr steel.

scholarly journals Preparation and Characterization of In Situ Carbide Particle Reinforced Fe-Based Gradient Materials by Laser Melt Deposition

Coatings ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 467 ◽  
Author(s):  
Weian Zong ◽  
Song Zhang ◽  
Chunhua Zhang ◽  
Chenliang Wu ◽  
Jingbo Zhang ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Steel Powder ◽  
Gradient Material ◽  
Wear Resistant ◽  
Gradient Materials ◽  
Melt Deposition ◽  
Surface Rigidity ◽  
Better Than

To obtain the wear-resistant camshaft with surface rigidity and core toughness and improve the service life of camshaft, wear-resistant Fe-based alloy gradient material was prepared by laser melt deposition. The traditional camshaft was forged by 12CrNi2V. In this paper, four types of wear-resistant Fe-based powders were designed by introducing various content of Cr3C2 and V-rich Fe-based alloy (FeV50) into stainless steel powder. The results showed that the gradient materials formed a satisfactory metallurgical bond. The composition of the phases was mainly composed of α-Fe, Cr23C6, and V2C phases. The increasing of Cr3C2 and FeV50 led to transform V2C into the V8C7. The microstructures were mainly cellular dendrite and intergranular structure. Due to the addition of Cr3C2 and FeV50, the average microhardness and wear resistance of gradient materials were significantly better than that of 12CrNi2V. The sample with 8% V had the highest microhardness of 853 ± 18 HV, which was 2.6 times higher than that of 12CrNi2V. The sample with 6% V had the best wear resistance, which was 21 times greater than that of 12CrNi2V.

Mechanical Characterization of Functionally Graded Materials with a Yield Strength Gradient

2001 ◽  
Vol 697 ◽  
Author(s):  
A. Nayebi ◽  
G. Mauvoisin ◽  
O. Bartier ◽  
R. El Abdi
Keyword(s):  
Yield Strength ◽  
Yield Stress ◽  
Mechanical Characterization ◽  
Functionally Graded ◽  
Spherical Indentation ◽  
Micro Hardness ◽  
Thermal Hardening ◽  
Graded Materials ◽  
Strength Gradient

AbstractAn elasto-plastic spherical indentation study on materials with a yield strength gradient, like steels which have undergone thermal hardening such as nitriding, is carried out using both experimental and finite element methods. A theory based on the evolution of hardness, is proposed to determine the yield stress and hardness profiles for materials with a decreasing yield stress with depth.Results for carbo-nitriding steels obtained by the standard Vickers micro hardness technique are compared with those obtained by the proposed method.

scholarly journals Fabrication and Characterization of In Situ Synthesized SiC/Al Composites by Combustion Synthesis and Hot Press Consolidation Method

Scanning ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Hongyu Yang ◽  
Erting Dong ◽  
Bingqi Zhang ◽  
Yanyan Yuan ◽  
Shili Shu
Keyword(s):  
Combustion Synthesis ◽  
Maximum Size ◽  
Holding Time ◽  
Mass Ratio ◽  
Hot Press ◽  
Uniform Size ◽  
Average Hardness ◽  
Sic Particles

The in situ SiC/Al composites were fabricated in Al-Si-C systems with different Si/C mass ratios and holding time by the method of combustion synthesis and hot press consolidation. The influences of Si/C mass ratio and holding time on the phase constitution, microstructure, and hardness of the composites were investigated. The results indicate that the increase of Si/C mass ratio leads to more uniform size distribution of the SiC particles in the Al matrix. Moreover, by improving the Si/C mass ratio from 4 : 1 to 5 : 1, the maximum size of SiC particle was reduced from 4.1 μm to 2.0 μm. Meanwhile, the percentage of submicroparticles was increased from 22% to 63%, and the average hardness value of the composites was increased by 13%. In addition, when the holding time is set to be fifteen minutes, the Al4C3 phase did not exist in the composites because of its total reactions with Si atoms to form SiC particles, and the average hardness value was 73.8 HB.

Processing and characterization of Ti–B-based functionally graded materials produced by microwave-activated combustion synthesis

2002 ◽  
Vol 17 (11) ◽  
pp. 2823-2830 ◽  
Author(s):  
M. Cirakoglu ◽  
S. Bhaduri ◽  
S. B. Bhaduri
Keyword(s):  
Combustion Synthesis ◽  
Functionally Graded ◽  
X Ray Diffraction ◽  
Entire Cross Section ◽  
Graded Materials ◽  
X Ray ◽  
Conventional Combustion ◽  
Titanium Monoboride ◽  
Graded Layers

Single as well as graded compositions were fabricated in the Ti–B system using a microwave-activated combustion synthesis (MACS) process. When synergistically combined with microwave processing, combustion synthesis offers great potential for the fabrication of ceramic structures and composites. Combustion waves were triggered using a SiC susceptor to initially absorb microwaves. The effects of processing variables, such as thermal insulation, and atmosphere on the process were investigated. Examination of reacted samples by means of x-ray diffraction indicated the presence of titanium monoboride and diboride along with unreacted titanium. Compared with conventional combustion synthesized products, MACS resulted in smaller pores. However, the total amount of porosity remained almost the same. The microstructure of the graded layers and interfaces were examined using optical and scanning electron microscopy. Over the entire cross section, the interfaces were continuous and crack free.

Preparation and Characterization of Multilayered Mullite/Mo Functionally Gradient Materials

2008 ◽  
Vol 368-372 ◽  
pp. 1866-1868
Author(s):  
Shu Heng Chen ◽  
Lin Jiang Wang ◽  
Xiang Li Xie ◽  
Ye Zhang
Keyword(s):  
Relative Density ◽  
Thermal Shock ◽  
Gradient Material ◽  
Thermal Shock Test ◽  
Composition Distribution ◽  
Shock Test ◽  
Gradient Materials ◽  
Functionally Gradient ◽  
New Phase

Multilayered mullite/Mo cermet functionally gradient material (FGM) was fabricated through a powder stacking process and sintering in vacuum up to 1500°C. The composition distribution, microstructure and microhardness of the FGM were analyzed. The results indicated that the mullite/Mo FGM was well densified with composite graded distribution and there was no new phase appeared. The microhardness of the FGM increase from 467HV to 1543HV, the density from 2.919 to 7.106 g/cm3 as the content of mullite increase from 20% to 80%. The relative density exceeded 90% as the content of mullite reached 80%. Thermal shock test showed that the cracks passed through the joint without deflection.

Characterization of Rh/Si multilayer structure by HREM and HAADF

1992 ◽  
Vol 50 (1) ◽  
pp. 122-123
Author(s):  
Y. Cheng ◽  
J. Liu ◽  
M.B. Stearns ◽  
D.G. Steams
Keyword(s):  
Normal Incidence ◽  
High Resolution Electron Microscopy ◽  
X Rays ◽  
Beam Direction ◽  
Cross Sectional ◽  
Optical Elements ◽  
Resolution Electron ◽  
Point To Point ◽  
Better Than

The Rh/Si multilayer (ML) thin films are promising optical elements for soft x-rays since they have a calculated normal incidence reflectivity of ∼60% at a x-ray wavelength of ∼13 nm. However, a reflectivity of only 28% has been attained to date for ML fabricated by dc magnetron sputtering. In order to determine the cause of this degraded reflectivity the microstructure of this ML was examined on cross-sectional specimens with two high-resolution electron microscopy (HREM and HAADF) techniques.Cross-sectional specimens were made from an as-prepared ML sample and from the same ML annealed at 298 °C for 1 and 100 hours. The specimens were imaged using a JEM-4000EX TEM operating at 400 kV with a point-to-point resolution of better than 0.17 nm. The specimens were viewed along Si [110] projection of the substrate, with the (001) Si surface plane parallel to the beam direction.

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