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Introduction Bimetal strips composed of two or more metal layers are being commonly used in a number of fields such as aerospace, automobile, and electrical industries due to their excellent combined properties.
The as cold rolled strip shows a fibrous microstructure with elaonggated grains and even obvious deformation bands.
With the further increase of annealing temperature, the microstructure become coarser and there is a sharp increase of grain size when the annealing temperature in increased from 700 to 800 oC.
With the increase of annealing time, the microstructure become coarser and some extra coarse grains appear when annealing for 180 mins.
(b) (a) (c) (d) Fig. 6 Microstructure of the aluminium brass alloy annealed at 700°C with different times a, 0.5h; b, 1h ; c, 1.5h; d, 3h Conclusions With the annealing of the aluminum brass alloy the microstructure is transformed from fibrous structure with elonggated grains and even obvious deformation bands to equiaxed structure with some annealing twins.

On the other hand, it is interesting to note that the GC cup wheel containing smaller abrasive grains reduced the truing force.
Few differences in the surface morphologies were observed between the two truing conditions, nor could the abrasive grain extrusion be identified clearly.
This is considered to be because the grain size of GC cup wheel used was too big and the feed rate of the cup wheel was not suitable.
A number of dulled abrasive grains showing abrasion wear were observed on the grinding wheel dressed without ultrasonication; few dulled abrasive grains and more clearly extruded grains appear on the grinding wheel dressed with ultrasonication.
Better grinding wheel surface condition in terms of the abrasive grain sharpness and the grain extrusion can be achieved by ultrasonicating the grinding wheel.

The SEM pictures of control and experimental samples after dehairing showing the grain surfaces and the cross section at a magnification of ×100 and ×200, respectively, are all shown in Figure 4.
It is seen that the grain surface appears to be more even and smoother in two experimental systems than control.
Fig. 4 Scanning electron micrographs of control and experimental samples after dehairing showing the grain surfaces and the cross section: (a) grain surface of enzyme-assisted dehairing by sulfide at a magnification of ××××100; (b) grain surface of enzyme-assisted dehairing by peroxide at a magnification of ××××100; (c) grain surface of control dehairing at a magnification of ××××100; (d) cross section of enzyme-assisted dehairing by sulfide at a magnification of ××××200; (e) cross section of enzyme-assisted dehairing by peroxide at a magnification of ××××200;(f) cross section of control dehairing at a magnification of ××××200.
Except for elongation at break, the other properties, such as tensile strength, tear strength and grain crack distention, etc., of two experimental systems are all slightly superior to that of the control samples.
Acknowledgements The authors thank Natural Science Foundation of Shaanxi University of Science and Tchnology for finance supports (contract grant number: ZX09-10) and Dr.

Also, it can take into consideration size and interfacial effects in DP steels due to varying the size of the martensite phase, the grain size of the ferrite phase, the size of embedded inclusions, the ferrite grain boundary effect, the ferrite-martensite interface effect, and the inclusion’s interface effect.
Also, debonding/separation at martensite/ferrite grains, ferrite/ferrite grain boundaries, and inclusion/ferrite or inclusion/martensite boundaries are not considered in the current study due to lack of experimental data needed to calibrate models for simulating such damage.
The irregular martensite grains are randomly distributed with an average island size in the range of to .
Raabe, "Deformation and fracture mechanisms in fine- and ultrafine-grained ferrite/martensite dual-phase steels and the effect of aging.
Raabe, "Orientation gradients and geometrically necessary dislocations in ultrafine grained dual-phase steels studied by 2D and 3D EBSD," Mater.

By subtracting this “mean” from the data one obtains a new function, which must have the same number of zero crossings and extrema.
A “coarse-graining” process is applied to the time series.
The length of each coarse-grained time series is N/τ. 2.
SampEn is calculated for each coarse-grained time series, and then plotted as a function of the scale factor.
Schematic illustration of the coarse-graining procedure for scale 2 and 3.

2# and 7# Fig .2 The curve of fine grain 3# and 13# When the clay content is relatively low, the cementation between the clays, accumulating disorderly around the silts, is weak.
The silts contact with each other and the basic structure is single-grained structure.
From the picture, the grading curves nearly coincide except the content of the relatively bigger grain size.
Fig. 3 The curve of fine grain 5#, 9# and 14# The m values which are approximate are 0.255, 0.204 and 0.249.
From the picture, the grading curves nearly coincide except the content of the relatively bigger grain size.

But refined grains can be obtained by adding Nb, which is favourable for high strengths after welding, and also adding Nb can reduce anisotropy in IF steels, therefore, compromises should be made in terms of the adding amount of Ti and Nb.
And the grain size of ferrite were nearly identical with size level keeping at I9 under different temperatures which explained niobium can effectively retard grain growth, and this properties would be favourable to enhance strengths of the steel after welding.
A number of steels were manufactured and samples were taken to make tensile testing.
Previously car produce had tested traditional Ti-IF steels products in spot-welding experiments which were found failed in some requirements such as tensile shear strength, nugget diameter, penetration rate and grain size.
Based on the microstructure result, the grain size was measured with around value of 90μm.

It is well known that the main effect of any severe plastic deformation (SPD) technique is strength enhancement due to grain size reduction to at least the submicrometer range.
In most investigation concerning Ti and its alloys, SPD is followed by cold rolling (CR) [4, 5]; normally the first step is performed at medium temperatures (400 – 600oC) employing a large number of ECAP passes.
The main difference consists in the directionality of deformation of the former process, and the rotation of preferential shear planes in the latter, which accounts for the grain refinement.
The equiaxed grains with d ≈ 12 μm, of sample 0X are replaced by a heavily deformed microstructure after four ECAP passes (where of course the individual grains cannot be imaged).
This outstanding result is probably due to the efficient grain refinement brought about by the eight passes, but elongation is less satisfactory, once compared with the 10% displayed by the Ti 6-4 alloy [TIMET datasheet – www.timet.com].

Compared to conventional coarse grained materials, the small grain sizes and high defect densities in UFG materials lead to high strengths and the occurrence of superplasticity [1].
The severe shearing deformation breaks the original microstructure into ultrafine or nanostructured material after a number of passes [2].
It reveals the presence of a high volume fraction of porosity, besides coarse grains.
The grain refinement promoted by ECAP is clearly shown in the micrograph of Fig. 5b.
We must stress that the grain size measurements were hindered by the presence of porosities.

Outermost Surface Diamond Grain Ta: Truncation depth G.
Outermost Surface Truncated Diamond Grain (a) Truing/dressing by ECD method (b) Cutting edge truncation Fig.2 Axial profiles of grinding wheel surface before and after truncation Fig.3 SEM images of diamond grain before and after truncation This unevenness of the wheel axial profile is completely removed by the cutting edge truncation, as is demonstrated in Fig. 2(b).
Fig. 3 shows a series of SEM images in which the change in shape of a specified diamond grain protruded from the bond matrix is shown with the progress of cutting edge truncation, namely, at the actual truncation depth of Ta = 0, 1, and 4 µm, respectively.
It can be seen that only the top of the diamond grain is truncated without any accompanying fractures, although small pits remain on the truncated surface.
Both the truncation force and the actual truncation depth increase nonlinearly with the set truncation depth because the number of contact points and the real contact area between the grinding wheel and the truncation tool are not proportional to the actual truncation depth.