Search results

A number of studies were carried out in the work, which included testing samples in a heat-treated state and free.
The structure includes a relatively small number of alloying elements.
The greater the indentation depth, the lower the hardness number HR.
The flat surface of the specimen was sequentially polished with various types of emery paper - first coarse-grained (M40), then medium-grained (P800; P1200), then fine-grained (P1500; P2000).
In comparison with the free state of the metal, where the structure is fine-grained, after heat treatment, the structure of the studied steel SS34 becomes homogeneous and an increase in grains is observed.

In situ tensile testing of ultra fine grained Pd and Pd-Ag alloys K.
This latter approach was used in our group to improve the strain hardening ability in a number of Pd-Ag alloys processed by high pressure torsion (HPT).
Results and discussion Grain scale analysis.
To further explore the problem, the in situ tensile testing was carried out for HPT-processed Pd and a number of Pd-Ag alloys to observe their deformation behaviour.
Fecht: Grain refinement and deformation behavior of ultra fine grained Pd and Pd-Ag alloys produced by HPT.

In the method, the fine-grained particles are subjected to partial melting and compacting.
Therefore, it is problematic to produce the ingots with fine-grained structure.
Therefore only a limited number of alloys having a wide solidus - liquidus range are used in these technologies.
As a result the granules with fine-grained structure (grain size ≈50 µm) or coarse-grained structure (grain size ≈350 µm) were formed correspondingly (Figure 1).
In the case of fine-grained granules the "reinforcement" possessed fine-grained structure.

Lattice sites having the identical Q number are considered as a grain, and a grain boundary segment is defined to lie between sites of different Q number.
NA and NB are the sites number of phase A and B, NC is the smaller sites number of that of phase A or B. δQiQj is Kronecker delta function, Qi and Qj denote the grain orientation state of the neighboring sites i and j.
Some grains significantly shrink, at the same time, some grains grow.
It can also be obviously seen that the number of nano-particles inside the matrix grains decreases with an increase in the size of nano-particles, this result is consistent with experimental observations that larger-sized nano-particles prefer to locate on the grain boundaries and smaller nano-particles often lie within matrix grains.
It can be found from Fig. 4 that the grain growth exponent decreases with increase of mean grain size for a given curve and to nearly zero when grain growth is pinned.

Qiu proposed the concept of coarse grain effect.
He believes in the process of fine particle flotation coarse grain to fine grained with a carrier, mediation and coagulation effect.
Powerful bubble washing way is beneficial to overcome the fine grained inclusion of gangue and nonselective reunion between mineral grains.
Microvesicles precipitation method is varied, such as in the pulp surface suction pulp caused negative pressure generated bubble, the electrolysis of water produced large numbers of micro bubble.
The research of fine grain carrier flotation hematite mechanism [J].

Due to the grain storage located in remote areas, the existing Monitor System for Grain is just monitored locally，and it is difficult to achieve remote monitoring.
Introduction Grain storage monitoring technology is one of the key technologies of scientific grain protection.
This system deploys a large number of wireless sensor nodes in the grain depot, which sample the grain temperature.
This system realizes remote temperature monitor of grain depot and data processing, and provides guarantees of scientific management of grain for administrators.
This system has been deployed in the actual grain depot, realizing the function of remote temperature monitor of grain depot.

The prepared particle reinforced aluminum matrix composite increased the number of nucleation during the process of solidification and enhanced the wear resistance, and refined the grain size, which can provide a strong basis for the new generation of light-weight and high-strength aluminum alloy drill pipe materials.
With the increase of TiB2 mass fraction (from 1wt. % to 3wt. %), the grain size of composites and grain boundary became smaller and cleaner, respectively (Fig. 1(b-d)).
When the addition amount reached to 3 wt. %, the grain was obviously refined and the flocs were mainly distributed at grain boundaries.
Compared with the 7075 aluminum matrix material, the grain boundaries of the composite with 1 wt. % TiB2 were clearer and the grain sizes were smaller.
The grain boundary of the obtained microstructure was clearer and cleaner.

Generation and motion of high angle grain boundaries are necessary to remove the deformed grains.
When a particle contacts the grain boundary and its surface replaces part of the grain boundary, the energy of the grain boundary is decreased.
dislocations due to their high number density and high thermal stability.
Consequently, both the nucleation and growth of recrystallized grains were retarded during solution heat treatment in the case of small a-dispersoids with high number density.
It was found that Mn could strongly affect the morphology and number density of the dispersoids.

This technique opens for studies of both overall grain growth as well as the growth of individual grains.
Due to the submicron grain structure after ECAP, and since the XRD experiments were to be carried out in a Laue transmission geometry, even thinner areas had to be made (~100-200 µm) in order to reduce the number of diffracting grains and to be able to treat them individually.
In-situ grain growth studies.
Note that the degree of rotation around PD varies from grain to grain.
Grain growth kinetics.

The morphology is characterized as the columnar grains at the periphery and equiaxed grains at the core.
The discharge voltage, U and pulse frequency, ω (the number of repetitions per unit time of a complete sinusoidal current waveform) are adjustable in the experiment.
The constitution of the morphology is equiaxed grains in the center and thin columnar grains in the edge.
The microstructures of pure Mg under 5Hz, 200V pulsed magnetic field (a) peripheral columnar grains transiting to exquiaxed grains, (b) centeral equiaxed grains.
It shows that the smaller average grain size in center, the shorter columnar grain size was formed in edge.