Ultra-precision diamond turning of optical silicon—a review
In traditional approach of silicon optical lens production, grinding, lapping, and polishing are employed. Success of these steps depends on the quality of the preceding ones; therefore, use of precision grinding is becoming an unwise decision during manufacturing of optical lenses with complicated surfaces. Owing to this, an alternate …
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Enhanced Oxidation Resistance of Ultrafine-Grain Microstructure
This work investigates the effect of ultrafine-grain microstructure on the oxidation behavior of AlCoCrFeNi high entropy alloy (HEA). The ultrafine-grain microstructure is obtained using stationary friction processing performed at two different rotational speeds, 400 and 1800 rpm, for 5 min duration. Processed samples demonstrate high depth of refinement …
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Ultrafine Friction Grinding of Lignin for Development of Starch
The work demonstrates the utilization of fractionalized lignin from the black liquor of soda pulping for the development of starch-lignin biocomposites. The effect of ultrafine friction grinding on lignin particle size and properties of the biocomposites was investigated. Microscopic analysis and membrane filtration confirmed the reduction of …
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Deformation induced grain boundary segregation in nanolaminated Al–Cu alloy
Before the surface mechanical grinding treatment (SMGT), alloy rods of 150 mm in length and 20 mm in diameter were solution treated at 540 °C for 6 h in vacuum followed by water quenching for obtaining supersaturated solid solution. ... Segregation of Cu along GBs was observed in an ultrafine grained Al–0.3 wt%Cu alloy prepared by …
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High Strain Behaviour of Ultrafine‑grained Aluminium Alloys …
ultrafine-grained aluminium alloys to study the various dynamic failure conditions such as unpredictable crashes, high rate grinding and machining, explosive fragmentation and …
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Ultrafine-grained aluminium alloys: processes, structural features …
This chapter provides a review of the processing techniques based on severe plastic deformation (SPD), namely high pressure torsion and equal channel angular pressing, as applied to age-hardenable and non age-hardenable Al alloys.
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Development of Ultrafine-Grained Al–Mg–Si Alloy Through
In the present investigation, ultrafine-grained Al alloy was produced from its bulk alloy by cryoforging followed by cryorolling. The bulk Al–Mg–Si alloy, with initial grain size 400 μm, was subjected to solid solution treatment (ST) followed by water quenching at room temperature. The ST treated alloy was subjected to aging at 100 °C for 4 and 8 h …
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Microalloying Ultrafine Grained Al Alloys with Enhanced Ductility
Ultrafine grained (UFG) Al alloys have attracted growing attention ... area of approximately 300×300 μm 2 and a 1 cm length were prepared by a combination of slicing and mechanical grinding.
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Alloying Elements Effects on Electrical Conductivity and …
2. Experimental. The experimental work was carried out on pure Al and four different Al alloys (Table 1) produced by direct chill casting in our lab to select the best option out of them.The commercially available aluminum, copper, silver and magnesium were weighed, added to the pure Al powder, and then heated in the graphite crucible at …
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Mechanical Behaviors of Ultrafine-Grained Ti-6Al-4V Alloy During
Ultrafine-grained (UFG) Ti-6Al-4V alloy with average grain sizes of 305, 430, and 669 nm was fabricated by high-energy ball-milling and spark plasma sintering. The mechanical behaviors of consolidated titanium alloy with different grain sizes were studied under uniaxial compression at the quasi-static strain rate of 1 × 10−3 s−1 and high strain …
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Effect of magnetic field on precipitation kinetics of an ultrafine
Alloys for TEM were mechanically grinding to a thickness of ~50 μm using SiC grinding paper from 800 to 3000 grit, followed by twin-jet electropolishing in a mixture 30% nitric acid and 70% methanol at −30 °C with a working voltage of 20 V. Observations were carried out on a JEOL 2100 F operating at 200 kV. ... Ultrafine grained Al 7075 ...
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Additive manufacturing of titanium alloys with enhanced strength …
For instance, Wang et al. [10] prepared Ti–Fe alloys with a combination of high strength and good ductility using elemental powders Fe and Ti. Zhang et al. [ 11 ] developed Ti–Cu alloys with both fine equiaxed prior-β grains and an ultrafine eutectoid lamellar structure by additive manufacturing, thereby contributing to promising ...
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Evolution of pitting corrosion resistance and mechanical
The aim of the present study was to determine the evolution of resistance to pitting corrosion and changes in the mechanical properties of ultrafine-grained aluminium during annealing. In contrast to the numerous papers devoted to the topic of the corrosion resistance of severely deformed aluminium alloys, a unique approach has been taken in …
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Development of ultrafine grained Al 7075 by cryogenic
The Al 7××× series alloys have extensively been applied in automobile and aerospace structures and other high strength components owing to their high strength-to-weight ratio, and high thermal and electrical conductivity.1–3 It is well known that refining the grain structure to ultrafine grained (UFG) regime can further enhance the mechanical …
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Advances in ultrafine-grained materials
Advances in ultrafine-grained materials. This review addresses new developments in the processing and properties of ultrafine-grained (UFG) materials. These materials are produced through the application of severe plastic deformation to conventional coarse-grained metals and typically they have grain sizes within the submicrometer or …
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Review on the progress of ultra-precision machining technologies …
Ultra-precision machining technologies are the essential methods, to obtain the highest form accuracy and surface quality. As more research findings are published, such technologies now involve complicated systems engineering and been widely used in the production of components in various aerospace, national defense, optics, mechanics, …
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Additive manufacturing of ultrafine-grained high-strength …
Furthermore, copper is a relatively low-cost alloying element and titanium–copper alloys can be additively manufactured with mixed elementary powders instead of with pre-alloyed powders ...
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Microstructure and Mechanical Properties of Powder
It is detected that Al content is higher while the Ti content is lower in the regions that are located in the single-phase layers. However, in the ultrafine-grained region, the Al content decreases rapidly. Meanwhile, the contents of Cr and Nb also decrease. This can be interpreted as the formation of more α 2 phase in the two-phase region ...
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Precipitation and aging phenomena in an ultrafine grained Al-Zn alloy
Ultrafine grained (UFG) 7075 Al alloy was processed by equal-channel-angular pressing (ECAP). ... TEM specimens were prepared by first mechanically grinding the samples to a thickness of about 20–30 μm, then dimpling to a thickness of about 10 μm, and finally ion-milling to a thickness of electron transparency using a Gatan Precision Ion ...
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Accelerated discovery of high-strength aluminum alloys by …
Aluminum alloys are attractive for a number of applications due to their high specific strength, and developing new compositions is a major goal in the structural materials community. Here, we ...
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Hierarchical nanostructured aluminum alloy with ultrahigh …
The alloy system is not fully amorphous because the Al content is 95%, which is beyond the glass forming region for Al-based MGs (Al content of 80–90% 27). The formation of Al nanocrystals leads ...
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A critical review of dispersion strengthened titanium alloy …
Hosokawa Micron Corp. originally created the mechanofusion dry powder coating technology for ultrafine material grinding and powder alloying ... 1/2 just as a reference applicable for Al alloys [112]. The mechanical properties of material have been shown to be highly influenced by grain size. Grain boundaries occur when grains have …
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Improving the grindability of titanium alloy Ti–6Al–4V with the
M. Nomura a, T. Fujii a Add to Mendeley https://doi/10.1016/j.cirp.2017.04.089 Get rights and content Abstract A novel …
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Production of ultra-fine grain microstructures in Al–Mg alloys by
1.. IntroductionThere are many potential advantages in the use of alloys with ultra-fine, or sub-micron grains for structural applications. At low temperatures aluminum alloys with sub-micron grain sizes have been shown to have higher elongation and yield strengths, compared to alloys with coarse grain sizes [1], [2], and it has recently been …
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Severe plastic deformation for grain refinement and
Abstract: This chapter is a review of the technique of severe plastic deformation, which converts coarse-grained metals into ultrafine-grained metals possessing a range of enhanced properties useful in modern applications. The chapter first describes the effects of grain size and grain boundaries on the properties of metallic materials and ...
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Ultra-precision grinding
The aim of ultra-precision grinding processes is to generate parts with high surface finish, high form accuracy and high surface integrity. For example, such processes are applied for the manufacturing of moulds for the replication of optical elements. In optical mould machining first a fine grinding process is applied yielding an acceptable ...
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Creep feed profile grinding of Ni-based superalloys with ultrafine
The grinding ratio, grinding forces, force ratio and ground surface roughness were evaluated through single-grain grinding of Ti–6Al–4V alloys. Experimental results indicated that the porous aggregated cBN wheels had abundant chip storage space and excellent wear resistance.
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Enhanced mechanical properties in ultrafine grained 7075 Al …
The enhanced strength resulted from high densities of Guinier–Preston (G-P) zones and dislocations. This study shows that severe plastic deformation has the potential to …
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Additive manufacturing of ultrafine-grained high-strength titanium alloys
Abstract. Additive manufacturing, often known as three-dimensional (3D) printing, is a process in which a part is built layer-by-layer and is a promising approach for creating components close to ...
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Precipitation Behavior during Aging Operations in an Ultrafine …
An ultrafine-grained (UFG) Al–Cu–Mg alloy (AA2024) was produced by surface mechanical grinding treatment (SMGT) with a high strain rate, and the precipitation behavior inside the grain and at the grain boundary was investigated. During SMGT, element segregation at the boundary was rarely observed, since the solute atoms were …
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