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And the main reason is that a large number of Cu large particles passed through HfSiN diffusion barrier layer and reacted with Si substrate and oxygen to generate Cu3Si and CuO with high resistance. 1.
From Fig. 1(e), the holes increased obviously, which illustrates that a large number of Cu large particles have passed through HfSiN diffusion barrier layer and reacted with Si substrate and oxygen to generate Cu3Si and CuO with high resistance, HfSiN thin film is failure for anti-diffusion to Cu.
Cu3Si(111) and CuO(002) diffraction peaks become sharp after being annealed at 700℃, which indicates that a large number of Cu large particles have passed through barrier layer, and barrier layer failure.
But there is no diffraction peak of HfSiN in the XRD patterns after being annealed at 700℃, which means that barrier layer failure is not caused by crystallization of barrier layer, but caused by a large number of Cu large particles passed through HfSiN diffusion barrier layer and reacted with Si substrate and oxygen to generate Cu3Si and CuO with high resistance.
The main reason is that barrier material generated large particles after annealing 30 min above 600℃, a large number of Cu large particles passed through barrier layer’s grain boundaries and reacted with Si substrate and oxygen to generate Cu3Si and CuO with high resistance.

This process is distinctly different from other sand casting processes as the process requires no binders for holding the sand grains together in the mould [24].
It was determined that sand grain shape, size and distribution have a pronounced effect on dimensional accuracy.
The results indicate that the sand grain fineness number and amplitude of vibration were the control factors.
The effect of process parameters, i.e. degree of vacuum, pouring temperature, grain fineness number, amplitude of vibration and time of vibration on the impact strength of Al-7% Si alloy castings in VAEPC process were investigated.

This kind of particle can penetrate a surface and locate itself in the grain boundaries and other defects of materials.
Several types of sites have been found to trap hydrogen, such as grain boundaries, vacancies, voids, dislocations, etc.
Hydrogen frequently leads to the degradation of material characteristics, diffuses through the grain-boundary and locates itself in the lattices.
The hydrogen tries to diffuse into, via grain boundaries, for example, and cause it to fail.
The hydrogen concentration at the trap sites CT is: CT = θTNT (9) where ���� is the occupancy of the trap site and ���� is the number of trap sites per unit volume [32].

One of the factors is the number of loads, which is taken into account by introducing a separate multiplier as a function of the number of loads N.
The number of applications of repeated loads is 106 and more.
The limit number of loads n is usually n=100…200.
Ling et. al., Permanent Deformation Characteristics of Coarse Grained Subgrade Soils under Train-Induced Repeated Load.
Article Number 03010 [21] P.

A higher number of S phases appeared in low-Zn/Mg ratio alloy during homogenization treatment compared with mid-Zn/Mg ratio alloy with a regime of 465°C/24h.
Alloy number Wt. % At. % Zn Mg Cu Zr Fe Si Al Zn+Mg Zn/Mg A1 7.27 1.82 2.04 0.1 ＜0.01 ＜0.005 Bal. 6.3 1.5 A2 7.78 1.61 2.02 0.1 ＜0.01 ＜0.005 Bal. 6.3 1.7 A3 8.03 1.42 1.94 0.1 ＜0.01 ＜0.005 Bal. 6.3 2.0 Results and Discussion Microstructure and DSC analysis of as-cast Al-Zn-Mg-Cu alloys The microstructure of three as-cast alloys under optical microscope (OM) are shown in Fig. 1.
Plenty of heterogeneous MgZn2 precipitates formed during the cooling of the ingots were observed around the grain boundaries [17].
In fact, the MgZn2 phase formed by Zn and Mg elements is only precipitated near the grain boundary, and its content is very small.

Furthermore, Finite Element (FE) analysis based on the experimental configuration was carried out to obtain the stress distribution on the contact surface, crack initiation location and number of cycles to the fretting fatigue failure were predicted based on the FE results.
In this paper, a circular arc dovetail attachment was designed and the tension fatigue experiment was also performed, the experiment results show a great fatigue performance and can satisfy the operating requirement for turbofan engine, furthermore, FE analysis of the experiment specimen was carried out, and the number of cycles to fretting fatigue was predicted based on the FE results as well.
TC4 alloy is a medium strength alloy which consists of α- and β-phase with a mean grain size of 10μm, the mechanical properties of this alloy are given in Table1.
For the convenience of analysing the variation of contact state at the edge of contact region under cyclic loads, the number of nodes is ordered regularly as shown in Fig. 2 (b).
The initial contact point on the tenon contact surface is node 8716, the node number increases from external to internal side of the contact region, a contact length of 128μm is concerned in this study based on the results of sliding distance from FE analysis.

Fe is mainly existed with impurities of FeAl3,T1,T2, and so on .When Fe content is slightly higher in the industrial pure aluminum and the content increases, the number, size of impurity phase will be also increased and aggregated distribution along the grain boundary.
They gathered at the grain boundaries and make condensate depression largen and refinement.
It also can change the form of Fe in aluminum alloys to reduce the needle-like grain, increase the spherical crystal[45].
Guan Ke-xiang et al.[46]have studied the rare earth industry to add aluminum and found that Ce with Fe and other impurities can product the high melting point intermetallic compounds in grain boundaries.
It can make rich-Fe impurity phase refinement and stabilize the grain boundary.

The presence of boron nitride, BN, in the coating, which positively effected a reduction in the oxygen content in the molten alloys, resulted in an increase in the number of cases of impermissibly high nitrogen content (Table 1).
These precipitates appeared as clusters at the grain boundaries and small particles inside the grains (Fig. 5).
A visible effect of rolling was the refinement of the grains and precipitates present in the microstructure (Figs. 8b, 9b), and this effect was particularly large in the alloy deformed at a higher temperature (Fig. 9b).
Summary The results of the authors' own previous studies and those conducted in this work on evaluating the possibility of melting titanium alloys in vacuum induction furnaces equipped with metal and ceramic crucibles and coated ceramic crucibles have indicated that the material of the crucible, the material and means of applying the coating, and the number of melts carried out in the crucible dictate the purity of the alloys.
Despite their presence, these alloys can be plastically deformed under multipass hot-rolling processes that produce high overall deformation, which results in considerable refinement of the grains and precipitates present in the microstructure.

In order to evaluate the restoration result, Equivalent Number of Look (ENL) and edge save index (ESI) are used as criterion.
As we know, fh(α) is the hausdorff dimension of the points where Hölder exponent equals α, while fg(α) evaluates the convergence speed of the probability that coarse grained exponents at resolution ε equals α when ε tends to 0.
We use denoising evaluation indexes, include equivalent number of looks (ENL) and edge save index (ESI), to estimate the images.
The ESI can then be written as[23]: Where m is the row number and n is the column number of the image.

After solution treatment the alloy was proceed with low-temperature ageing treatment, a large number of dispersively tiny phases precipitated in the matrix of the alloy, which exhibits strengthening action.
The number, size, shape and distribution of precipitated phases in the alloy were the key factor which affected the strength of the alloy, so increase the number of precipitated phases in alloy and improve the morphology and size of strengthening phase can significantly increase the mechanical properties of alloys [2-5].
With the increase of the second-phase number, the dispersion strengthening effect more obvious.
TEM microstructure of cast Al-5.5Fe-4Cu-2Zn-0.4Mg-0.5Mn alloys (a)Precipitated phase after T6 heat treatment(b)Precipitated phase after T6 heat treatment Conclusions (1) After T6 heat treatment, the tensile strength of casting Al-5.5Fe-4Cu-2Zn-0.4Mg-0.5Mn alloy improved significantly, grains are fine and well-distributed