scholarly journals Diffusion Bonding of FGH 98 and CoCrNi-Based Medium-Entropy Alloy: Microstructure Evolution and Mechanical Tests

Crystals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1158
Author(s):  
Yajie Du ◽  
Zhaoxi Li ◽  
Jiangtao Xiong ◽  
Yipeng Chen ◽  
Shiwei Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Diffusion Bonding ◽  
Bonding Temperature ◽  
Mechanical Tests ◽  
Strengthening Effect ◽  
Fracture Feature ◽  
The Matrix ◽  
Alloy Microstructure ◽  
Coherent Relationship ◽  
Maximum Shear Strength

The superalloy FGH98 was successfully diffusion bonded (DB) with medium-entropy alloy (MEA) Al3Ti3(CrCoNi)94 using pure Ni as the interlayer at a temperature range of 1050–1170 °C for 1 h under 5 MPa. The microstructure and mechanical properties of joints were investigated. The diffusion bonding seam was composed of an interlayer zone (IZ) and two diffusion-affected zones (DAZ). The IZ and DAZ beside the FGH98 consisted of cubic Ni3(TiAl)-type γ′ phases due to the diffusion of Ti and Al atoms. Meanwhile, the DAZ adjacent to the MEA consisted of spherical γ′ phases. Both of the γ′ phases with different morphology kept the coherent relationship with the matrix. Moreover, increase of bonding temperature led to the morphology of interlayer γ′ phase to transform from sphere to cube. Due to the strengthening effect of a mass of γ′ phase distributed evenly in IZ and the DAZ beside the FGH98, the microhardness and Young’s modulus of these two zones were higher than that of DAZ near the MEA. The maximum shear strength of DB joint, 592 MPa, was achieved in the joint bonded by 1150 °C, which was the typical ductile fracture feature confirmed by the shear dimples.

scholarly journals Diffusion Bonding of Ti6Al4V at Low Temperature via SMAT

Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 94
Author(s):  
Yuqing Chen ◽  
Guofeng Wang ◽  
Yongkang Liu ◽  
Liqiang Zhan ◽  
He Diao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Diffusion Bonding ◽  
Welded Joint ◽  
Surface Mechanical Attrition Treatment ◽  
Mechanical Attrition ◽  
Long Time ◽  
Tc4 Alloy ◽  
Heat Preservation ◽  
Maximum Shear Strength

Titanium alloys used to be welded to gain good joint strength at 920 °C through diffusion bonding. However, due to the heat preservation at high temperatures for a long time, we obtain joints with great bond strength while the mechanical properties of the sheet are lost. In this paper, taking Ti6Al4V alloy as an example, we studied the microstructure of the surface under the different times of surface mechanical attrition treatment (SMAT). In addition, the microstructure and mechanical properties after diffusion bonding at 800 °C-5 MPa-1 h were also conducted. The results show that the shear strength of TC4 alloy welded joint after SMAT treatment is improved, and the maximum shear strength can reach 797.7 MPa, up about 32.4%

scholarly journals Superplastic Forming and Reaction Diffusion Bonding Process of Hollow Structural Component for Mg-Gd-Y-Zn-Zr Rare Earth Magnesium Alloy

Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 152
Author(s):  
Peng Peng ◽  
Shaosong Jiang ◽  
Zhonghuan Qin ◽  
Zhen Lu
Keyword(s):  
Mechanical Properties ◽  
Diffusion Bonding ◽  
Structural Component ◽  
Bonding Temperature ◽  
Reaction Diffusion ◽  
Superplastic Forming ◽  
Tensile Tests ◽  
Interface Roughness ◽  
Size Growth ◽  
Cu Interlayer

This work fabricated a double hollow structural component of Mg-8.3Gd-2.9Y-0.8Zn-0.2Zr alloy by superplastic forming (SPF) and reaction-diffusion bonding (RDB). The superplastic characteristic and mechanical properties of Mg-8.3Gd-2.9Y-0.8Zn-0.2Zr alloy sheets at 250–450 °C were studied. Tensile tests showed that the maximum elongation of tensile specimens was about 1276.3% at 400 °C under a strain rate of 1 × 10−3 s−1. Besides, the effect of bonding temperature and interface roughness on microstructure and mechanical properties of the reaction diffusion-bonded joints with a Cu interlayer was investigated. With the increase of temperature, the diffusion coefficient of Cu increases, and the diffusion transition region becomes wider, leading to tightening bonding of the joint. However, the bonding quality of the joint will deteriorate due to grain size growth at higher temperatures. Shear tests showed that the highest strength of the joints was 152 MPa (joint efficiency = 98.7%), which was performed at 460 °C.

Effects of Bagasse Fiber on Crystallization, Morphological and Mechanical Properties of Poly(Lactic acid)

2012 ◽  
Vol 602-604 ◽  
pp. 708-711
Author(s):  
Jun Cai ◽  
Nan Shi ◽  
Qiang Dou
Keyword(s):  
Mechanical Properties ◽  
Flexural Modulus ◽  
Mechanical Tests ◽  
Silane Treatment ◽  
Melt Blending ◽  
Scanning Calorimetry ◽  
Crystallization Ability ◽  
The Matrix ◽  
Bagasse Fiber ◽  
Melting And Crystallization

Polylactic acid (PLA)/bagasse fiber (BF) composites were prepared via melt blending. The melting and crystallization behavior, morphology and mechanical properties of the composites were studied by means of differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and mechanical tests. The results indicate that the crystallization ability of PLA is improved with the addition of BF. Silane treatment improves the adhesion between BF and the matrix. Compared with pure PLA, the flexural modulus increases, while the notched impact strength decreases for BF/PLA composites.

scholarly journals Effects of the Mg/Si Ratio on Microstructure, Mechanical Properties, and Precipitation Behavior of Al–Mg–Si–1.0 wt %-Zn Alloys

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2591 ◽  
Author(s):  
Yong Li ◽  
Guanjun Gao ◽  
Zhaodong Wang ◽  
Hongshuang Di ◽  
Jiadong Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Volume Fraction ◽  
Solution Treatment ◽  
Hardness Test ◽  
Strengthening Effect ◽  
Precipitation Behavior ◽  
Scanning Calorimetry ◽  
First Choice ◽  
The Matrix ◽  
Zn Alloys

Aluminum alloys are widely used as first-choice materials for lightweight automotive applications. It is important that an alloy have a balance between strength and formability. In this study, the alloys were melted, cast, hot rolled, and cold rolled into 1 mm-thick sheets. The microstructure, mechanical properties, and precipitation behavior of Al–Mg–Si–1.0 wt %-Zn alloys with Mg/Si ratios of 0.5, 1, and 2 after solution treatment were studied using optical and electron microscopy, a tensile test, the Vickers hardness test, and differential scanning calorimetry. The results showed that a high density and number of Al–Fe–Si particles were observed in the matrix, thus causing the formation of more homogeneous and smaller recrystallized grains after treatment with the solution. In addition, a higher volume fraction of cubeND and P-types texture components formed during solution treatment. Also, a high r value and excellent deep drawability were achieved in the medium-Mg/Si-ratio alloy. The formation of denser strengthening precipitates led to a better paint-bake hardening effect in comparison with the other two alloys. Furthermore, the precipitation kinetics were enhanced by the addition of Si, and the addition of Zn did not alter the precipitation sequence of the Al–Mg–Si alloy. The dual-phase strengthening effect was not achieved in the studied alloys during paint-bake treatment at 175 °C.

Microstructure and Mechanical Properties of a Single Crystal NiAl Alloy with Zr or HF Rich G-Phase Precipitates.

1990 ◽  
Vol 213 ◽  
Author(s):  
I. E. Locci ◽  
R. D. Noebe ◽  
R. R. Bowman ◽  
R. V. Miner ◽  
M. V. Nathal ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Single Crystal ◽  
Single Crystals ◽  
Heat Treatments ◽  
Strengthening Effect ◽  
Slow Cooling ◽  
Large Plate ◽  
Nial Alloy ◽  
Large Particles ◽  
The Matrix

ABSTRACTThe possibility of producing NiAl reinforced with the G-phase (Ni16X6Si7), where X is Zr or Hf, has been investigated. The microstructures of these NiAl alloys have been characterized in the as-cast and annealed conditions. The G-phases are present as fine cuboidal precipitates (10 to 40 nm) and have lattice parameters almost four times that of NiAl. They are coherent with the matrix and fairly resistant to coarsening during annealing heat treatments. Segregation and non-uniform precipitate distribution observed in as-cast materials were eliminated by homogenization at temperatures near 1600 K. Slow cooling from these temperatures resulted in large plate shaped precipitates, denuded zones, and a loss of coherency in some of the large particles. Faster cooling produced a homogeneous fine distribution of cuboidal G-phase particles (≤10 nm) in the matrix. Preliminary mechanical properties for the Zr-doped alloy are presented and compared to binary single crystal NiAl. The presence of these precipitates appears to have an important strengthening effect at temperatures≥1000 K compared to binary NiAl single crystals.

Modeling Relations between Processing, Microstructure and Mechanical Properties of Porous Bioceramics

2006 ◽  
Vol 15-17 ◽  
pp. 519-524
Author(s):  
Franck Tancret ◽  
Jean Michel Bouler
Keyword(s):  
Mechanical Properties ◽  
Fracture Stress ◽  
Biphasic Calcium Phosphate ◽  
Bending Strength ◽  
Bone Substitutes ◽  
Mechanical Tests ◽  
The Other ◽  
The Matrix ◽  
The One ◽  
Porous Bioceramics

Biphasic calcium phosphate (BCP) bioceramics, for use as resorbable bone substitutes, containing both isolated macropores and interconnected micropores, have been fabricated by sintering, using naphtalen particles as a porogen to produce macropores. The resulting ceramics contain ~ 45% macropores and various amounts of microporosity. Mechanical properties (compression and bending strength, toughness and hardness) have been measured and modeled by combining two approaches, at two different scales: the one describes the mechanical properties of a partly sintered stacking of grains, supposed to account for the interconnected microporosity, the other one holds in the case of closed and isolated macropores within a continuous matrix. The material is then represented as a quasi-continuous matrix containing macropores, the matrix being itself microporous. The model also considers that fracture always initiates on a macropore, which allows to set a correspondence between fracture toughness and fracture stress equations. The mechanical tests performed on the sintered ceramics tend to validate the modeling approach.

Mechanical and microstructure property evaluation of diffusion bonding of 5083, 6061 and 7075 aluminium to AZ31 magnesium using Cu interlayer

2021 ◽  
pp. 095440542110144
Author(s):  
Nader Nadermanesh ◽  
Abdolhamid Azizi ◽  
Sahebali Manafi
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Diffusion Bonding ◽  
Bonding Temperature ◽  
Effect Of Temperature ◽  
Process Conditions ◽  
Micro Hardness ◽  
Bonding Pressure ◽  
Electron Microscopes ◽  
Cu Interlayer

The diffusion bonding of 7075, 6061 and 5083 aluminium alloys to AZ31B magnesium was investigated using copper interlayer. An optical microscope along with scanning electron microscopes, equipped with an energy dispersive spectrometry/electron probe microanalysis, was utilized to characterize the microstructure of the joint. The mechanical properties of the joint were also assessed by micro-hardness and shear strength tests. The results indicate the high effect of temperature on the bonding results; so that, with a small change in temperature, severe changes were observed in the bonding results. A temperature range of 475°C–485°C and a minimum duration of 30 min with a low bonding pressure of 0.4 MPa were identified as advisable process conditions. The joint evaluation revealed the formation of CuAl2, Cu9Al4 and Al-Mg-Cu ternary phases on the aluminium-copper side, as well as Cu2Mg, CuMg2 and Al-Mg-Cu ternary phases on the magnesium-copper side in the reaction layer. When increasing the bonding temperature and duration, the amount of intermetallic compounds and, as a result, the mechanical properties of the joints changed. The highest shear strength and micro-hardness, related to the bonding performed at 480°C and holding time of 45 min, were 31.03 MPa and 167 HV, respectively.

scholarly journals Evaluation of Mechanical Properties of GFRP Composites with Fillers

2019 ◽  
Vol 8 (11) ◽  
pp. 3997-4001
Keyword(s):  
Mechanical Properties ◽  
Composite Material ◽  
Environmental Conditions ◽  
Mechanical Tests ◽  
Flexural Properties ◽  
Filler Materials ◽  
Gfrp Composites ◽  
Gfrp Composite ◽  
The Matrix ◽  
Day By Day

The usage of GFRP composites are gradually increasing day by day because of its unique properties over conventional metals. GFRP composite materials are much stronger and contain less weight than the metals which are using in more industries like Automobiles. And it was noticed that the properties of the GFRP composites are decreasing noticeably in certain environmental conditions. So, it is important to improve the quality and mechanical properties of the GFRP composites that they use to odder environmental conditions. From the farmer literature it was observed that adding filler materials to the composite adhesive can enhance the strength and properties of the composite material. In this investigation two filler materials (Znso4, talc) are added to the composites in certain ratios (1%,3%,5% and 7%). And to observe the mechanical properties specimens are placed in water for 30 days, and mechanical tests were performed on the specimens. And It was observed when fillers are added to the matrix of the composite the mechanical properties are increased when it compares to the no filler added composites. Properties are enhanced when the certain ratio of filler were added. Again properties are decreased when the high amount of fillers were added. And high tensile properties were observed when the 3% of filler added. And flexural properties and ILSS properties are enhanced when 1% of filler added.

scholarly journals Microstructure and Mechanical Properties of Carbide Reinforced TiC-Based Ultra-High Temperature Ceramics: A Review

Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1444
Author(s):  
Haobo Mao ◽  
Fuqiang Shen ◽  
Yingyi Zhang ◽  
Jie Wang ◽  
Kunkun Cui ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Solid Solution ◽  
High Temperature ◽  
Bending Strength ◽  
Second Phase ◽  
Strengthening Effect ◽  
Dispersion Strengthening ◽  
The Matrix ◽  
Ultra High Temperature

TiC ceramics have become one of the most potential ultra-high temperature structural materials, because of its high melting point, low density, and low price. However, the poor mechanical properties seriously limit its development and application. In this work, this review follows PRISMA standards, the mechanism of the second phase (particles, whiskers, and carbon nanotubes) reinforced TiC ceramics was reviewed. In addition, the effects of the second phase on the microstructure, phase composition and mechanical properties of TiC ceramics were systematically studied. The addition of carbon black effectively eliminates the residual TiO2 in the matrix, and the bending strength of the matrix is effectively improved by the strengthening bond formed between TiC; SiC particles effectively inhibit the grain growth through pinning, the obvious crack deflection phenomenon is found in the micrograph; The smaller grain size of WC plays a dispersion strengthening role in the matrix and makes the matrix uniformly refined, and the addition of WC forms (Ti, W) C solid solution, WC has a solid solution strengthening effect on the matrix; SiC whiskers effectively improve the fracture toughness of the matrix through bridging and pulling out, the microscopic diagram and mechanism diagram of SiC whisker action process are shown in this paper. The effect of new material carbon nanotubes on the matrix is also discussed; the bridging effect of CNTs can effectively improve the strength of the matrix, during sintering, some CNTs were partially expanded into GNR, in the process of crack bridging and propagation, more fracture energy is consumed by flake GNR. Finally, the existing problems of TiC-based composites are pointed out, and the future development direction is prospected.

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