Search results

The number of parts produced by HSS was about 3 million parts per year in 1987, and it raised up to 107 million parts per year in 2007 [1].
In Eq. 1, f(G), f(T) and f(Xi) describes the impact on phase transformation of austenite grain size, temperature and volume fraction of phase.

The SEM observations (not shown) exhibit that the grain size of ZrB2 matrix is remarkably smaller than that of the monolithic ZrB2 and the excessive growth was inhibited.
The SEM observa- tions show that the ZrC contained composites possess a large number of SiC whiskers without degradation, suggestingd that the diffusivity of whisker could decrease effectively by addition of ZrC.

But using it to braze stainless steel, the welded joint is easy to generate intermetallic compounds and grain boundary penetration brittle etc[2-4].
That showed, there were a large number of brittle and hard compounds, and because of solid solution, the hardness nearby the base material and welded joint was lower.

All confining systems were applied “as usual”, that is with a single textile (or fabric) sheet wrapped around each specimen until the desired number of layers was achieved.
Here, “conventional wrapping” corresponds to a single textile sheet being wrapped around the shear span until the desired number of layers is achieved.
These strengthening schemes were selected in this study so that they would provide useful insight into the effects of the fiber reinforcement ratio and the number of TRM layers (of equivalent axial rigidity).
Moreover, regardless of the matrix material (polymer-modified mortar versus epoxy resin), the strength generally increases with the number of layers and the axial load, at the expense of deformation capacity.
Weak textile-to-mortar bond regions were evident when mortar with finely-grained sand was used in combination with uncoated fiber meshes; this was attributed to the stickiness of the mortar (i.e. to the high plastic viscosity of the mixture) that led to poor mortar penetrability in the fiber bundles and to reduced failure load compared to the counterpart specimen comprising a TRC SiP form made of a coarse-grained mortar.

Although the proof of principle has been obtained some time ago, recently a number of studies have been published aimed at optimising the joining operations to obtain best joint strength and reduced distortion and residual stress.
Strength is also improved due to a variety of mechanisms, including grain refinement, creation of additional obstacles to dislocation movement, etc.

Commonly, steels like AISI 316L with a high resistance to HEE include a large number of alloying elements and in high amount.
The nickel equivalent number Nieq in Eq. 2 was used to assess the AusStab against martensitic transformation, calculated according to the empirical equation of Zhang et al. [7].
Nieq(%) = Ni + 0.65Cr + 0.98Mo + 1.05Mn + 0.35Si + 12.6C (2) The benefit of the Nieq number is the threshold value of 27 %.
Acknowledgements The authors gratefully acknowledge the financial support of the Deutsche Forschungsgemeinschaft under DFG-Project number WE 4436/4-1.
Ohashi, Composition and Grain Size Dependencies of Strain induced Martensitic Transformation in Metastable Austenitic Stainless Steels, J.

Analysis of the possibility of own stresses steering can be realized by changing factors: regular outline of the asperity (triangular, rounding, rounding-linear) and their parameters (height, vertical angle, rounding radius), asperities space, depth of pile and smooth burnishing, number of upcoming one by one crossing in hybrid burnishing (embossing of asperity and their burnishing), position of the burnishing tools in the next steps.
According to preliminary analysis, the ability to internal stress distribution control can be realized by change the following factors: outline of the regular asperities (triangular, arc, arc-line), and its parameters (height, apex angle, corner radius, etc.), asperities feed, depth of uplift burnishing, and depth of smooth burnishing, the number of duplex burnishing passes.
Analysis of the possibilities of stresses distribution control can be realized through changes of the following factors values: outline of the regular asperities (triangular, arc, arc-line), its parameters (height, apex angle, corner radius, etc.), distance between the asperities, depth of uplift burnishing, depth of smooth burnishing, the number of duplex burnishing passes (asperities embossing and squashing), the tools setting in the following passes.
Kukielka: Numerical analysis of states of strain and stress of material during machining with a single abrasive grain.
Patyk: Theoretical and experimental basis of regular asperities about triangular outline embossing technology, Steel Research International Special Edition, Volume 81, Number 9, Publishing Company Verlag Stahleisen (2010), pg. 190 - 193.

Experiments with Central Composite Face-centered (CCF) design were performed to save the number of experimental runs.
Sand Type Roundness AFS Grain Size %SiO2 pH Brightness (Lux) Phenolic Resin Type Gelation Time (sec) Flow Length (mm) Shape S1 (40%) 1.32 55-60 93 7 44 R1 (70%) 29 48 Needle S2 (30%) 1.18 99 7 78 R2 (30%) 35 100 Needle S3 (30%) 1.25 99 7 75 Methods.
Response surface methodology with central composite design was applied since it helps save the total number of experimental runs and can estimate the interaction effects.
Second, experiments with Central Composite Face-centered (CCF) design were performed to save the number of experimental runs and inverstigate the interaction effects.

The researchers used a high-frequency solid-state laser with a wavelength of 1.06 μm and continuous radiation of a gas laser on carbon dioxide with a wavelength of 10.6 μm to break the metal bond, remove adhering chips, level the profile, control the protrusion of abrasive grains, and profile circles.
Naming and designation of factors Levels of variation Intervals of variation – 0 + Processing speed [mm/s] 10 15 20 5 Radiation power [W] 40 50 60 10 Let's introduce designations: х1 is processing speed; х2 is radiation power, which are coded factors, varying at two levels; N is number of experiments; j is the number of the experiment (j = 1, 2,…, N); n is the number of repeated measurements in the j-th experiment; y is the response function; is the average value of the response function.
Since the number of factors is small (two), it was decided to conduct a full factorial experiment of type 22, where the number of factors k = 2, the number of levels p = 2, the number of experiments N = 4, and the number of repeated experiments n = 5.
With the same number of parallel experiments for each combination of factor levels, the reproducibility of the process (the absence of significant deviations) is determined by the Cochran criterion.
(7) The value of the Student's coefficient t (P; fE) for the confidence probability P = 0.95 and the number of degrees of freedom fE = N × (n – 1) =16 was taken from [16].

In order to improve the wetting property of the melted powder, the plate surface was sandblasted with #35 of average grain size[5].
The thickness of the beam model which was varied by the number of forming layers was ranged 1 - 30 mm.
Fig. 6 showed the influences of the layered number on the base plate deformation and the residual stress at the consolidated surface under the base plate height of ts=20 mm.
The deformation height and residual stress increased with the increase of the layered number, and then became almost constant when the layered number was over 400 layers.
The increase of the residual stress was due to the increase of the consolidated layer, which was equal to the laser irradiation number.