Search results

This comprised some 50% of the total number of contributions.
Vacancies at grain boundaries appeared to be shallow traps for positrons.
A number of other topics were studied, including: effects of the As-vapour pressure on vacancy concentration in GaAs, VSi in electron irradiated 6H-SiC, activation of dopants in B- and Al-ion implanted SiC, voids in Al- and N-ion implanted ZnO, Zn associated defects in GaP with Znimpurities.
Final Remarks In this conference there was a considerable number of contributions on metals and metal alloys, a little more, relatively, (23% of the total) than in ICPA12 (20%) [1].

Samples with dimensions of 10 x 10 x 10 mm were cut from ingots and ground using abrasive papers with grain sizes of 500 and 1200.
Surface morphology of WE43 alloy after 0 h (a), 72 h (b), 168 h (c), and 336 h (d) of immersion in 0.1M Na2SO4 solution saturated with Mg(OH)2 The scale seems to be relatively compact with a small number of micro-cracks, but without apparent discontinuities (Figs 1b-d).
Microstructure observations of the sample cross sections confirmed the absence of spallation in the scale, but reveal a large number of micro-cracks occurring throughout the entire volume of the scale (Figs 2b, c).
Microstructure on the cross section of AE44 alloy after 0 h (a), 72 h (b), 168 h (c), and 336 h (d) of immersion in 0.1M Na2SO4 solution saturated with Mg(OH)2 Also, microstructure observations on sample cross sections confirmed the occurrence of spallation and a large number of micro-cracks occurring throughout the entire volume of the scale (Figs 5b-d).

High demands on the accuracy and quality become strict if it is necessary to manufacture elements with small-size periodic profile, for example, fine-grained tooth-wheels for transmission nodes or slots with a complex profile and etc.
The appearance and reamer in diameter of heavy-duty mill with the constructive feed (a); reamer in diameter of mill with “helical backing-off” (b) Тhis tool has a number of advantages and disadvantages, both in terms of operational characteristics or dynamics of the machining process as well as from the viewpoint of physical processes occurring in the zone of contact of the tool with the work-piece.
For example, increasing the feed per tooth by decreasing the number of teeth in the annular circular row should significantly reduce tool life, in the design of which axial constructive feed is laid.
A number of papers [3,4,5] has been devoted to the research in the field of the tooling design and tooling operation with constructive feed, however, the questions of their wear properties are not lit enough.

Fe % Cr % Ni % Mo % Mn % S % 64.46 17.556 11.889 2.482 1.490 0.017 The average size grain of the steel, as measured by scanning electronic microscope observation (Fig.1), is estimated to 10 µm.
Evolution of crack size vs number of cycles The figure 5 indicates that a decrease in the load frequency is accompanied by an increasing of the crack opening, over the whole fatigue test.
For a same number of cycles, the sample is much longer solicited mechanically and exposed to the chemical medium, for the low frequency than the higher one.
The time appears then a more significant factor than the number of cycles of corrosion-fatigue.

Magnesium wrought alloy AZ31B with average grain size of about 23 µm was used.
The number of cycles to first turning point was designated as Ni, crack initiation life, and the number of cycles to second turning point was designated as Nrp, which composed of crack initiation and slow propagation.
In order to normalize all the results obtained from different solution concentration, Table 1 summarizes the ratio of the crack initiation life Ni to the total number of cycles to failure Nf and the ratio of Nrp to Nf.

Cu-Ca alloys were vacuum induction melted to cast cylinder type ingots. 10~15% cold working of ingots by simple compression was done to get globular grains by SIMA mechanism during reheating of billets to semi-solid temperatures.
The design, the number and the size of slots should be varied if the capacity of induction motor is changed.
For example, the slot height and the slot number of 60W rotor core are reduced to 25 mm and 30, respectively, which will make the control of processing conditions easier.
The numbers on the micrographs mark the locations of microstructural sampling, that is,1 is the bottom and 5 the top of rotor.

They require prescription of a large number of input parameters (effective thermal conductivity, effective viscosity, surface tension, etc.), which, in turn, are dependent on the problem solution [3-4].
where N is the number of observations, K is the number of unknown parameters, fnm and fn are the respective measured (prescribed) and calculated weld characteristics, wnf and wkp are the weighting factors, pk0 is the guessed value of the kth parameter pk, qmax is the peak allowable value of power q.
Solution of inverse heat conduction problem for determining heat input, weld shape, and grain structure during laser welding // Science and Technology of Welding and Joining. – 2002. – Vol. 7, N 2, – P. 224-231

ARIMA allows short-term and long-term forecasts ranging from one to an arbitrary number of steps ahead.
The Parameters of the ARIMA Model To succinctly describe non-stationary or seasonal series, the ARIMA M(p,q) model can be extended to construct general ARIMA models, allowing an arbitrary number of regular (d>=1) and seasonal (D>=1) difference levels.
The d, which is the number of differences needed to make the data stationary .In our case it was d=1 for all the plugins.
Lei lu-lu, Du Hong-fei Application of B-J Model for non-stationary time-serial analysis in deformation prediction Science of Sureying and Mapping 37(5): 207.209,226,( 2012) [3] Liu yangfang,Chen qihua,Ding linlei Application of combination gray model in deformation prediction Geotechnical Investigation & Surveying (1):58-60,( 2013) [4] Huo xin-lin, Chang ping-fan, Bai lei Time series forecasting of the trend of total food-grain consumption in china journal of shanxi agricultural univercity (social science edition) ,3(4):317-320, (2001) [5] Ni hai-er, Zhou rui-juan Combined Time series Models for the Dynamic Analysis of the Fisheries Resources journal of natural resources 26(6):992-998,(2011) [6] YAN Li- ping, LING Jian- zhong, LI Jian- sheng, et al.

It appears that the average crack width is maintained for a significant range of tensile strain, while the number of cracks increases with increasing imposed strain.
Coefficient of Permeability, [m/sec] In Figure 2 the total permeability and the permeability normalised by the number of cracks in the specimen are compared for a particular SHCC and reinforced mortar at various levels of crack width.
Observed Permeability Normalized Permeability 1.00E+00 1.00E-01 1.00E-02 1.00E-03 1.00E-04 1.00E-05 1.00E-06 1.00E-07 1.00E-08 1.00E-09 1.00E-10 1.00E-11 1.00E-12 0 100 200 300 400 500 600 Crack Width, w[μm] Fig. 2 Water permeability of SHCC and steel mesh reinforced mortar normalised by the number of cracks [9].
Cement of the experiment is P.O 42.5, and the maximum grain size is 0.3 mm.

However, despite efforts made over a number of years, the control of the industrial casting process remains unsatisfactory.[3] What’s more, pouring temperature is one of the important process parameters of directional solidification.
A.Onyszko et al.[4] introduced Bridgman preparation technique to produce the CMSX-6 superalloy turbine blades, and, Stanisaw Roskoszso et al.[5] investigated methodology of quantitative evaluation of porosity, dendrite arm spacing and grain size in directionally solidified blades made of CMSX-6 nickel alloy, but they did not make a deeper investigation about the process parameters such as pouring temperature.
The segregation of Al and Ti are more serious, so the size of eutectic is slightly larger, but the number is smaller.
With the higher pour temperature, just as shown in Fig.4(b), temperature gradient is improved, this results the volume of mushy zone is smaller, so the branch crystal organization becomes refinement with reducing of the primary dendrite arm spacing, due to branch crystal organization refinement, so the number of branch crystal is more, it makes branch crystal between residual liquid phase increased, the more residual liquid phase which reaches eutectic composition,the more content of eutectic.