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Online since: November 2011
Authors: Hai Lian Qin, Gui Hua Peng, Zhen Hua Liang, Xiao Xia Liu
The results showed that the AZO powders were well-distributed with smaller grain size when using dual fuel.
And it benefits the grain growth and improving the performance of AZO powders.
But there are large numbers of gray-black impurities in the bottom of crucible of the S3 sample, the reason is that the sample could not be calcined completely because of excessive citric acid.
The grain size reaches between 100 to 200nm.
However the S2 sample is well-distributed and the grain size is about 30 to 40nm.
And it benefits the grain growth and improving the performance of AZO powders.
But there are large numbers of gray-black impurities in the bottom of crucible of the S3 sample, the reason is that the sample could not be calcined completely because of excessive citric acid.
The grain size reaches between 100 to 200nm.
However the S2 sample is well-distributed and the grain size is about 30 to 40nm.
Online since: October 2010
Authors: Ye Hua Jiang, Yao Liu, Yun Ying Fan, Rong Zhou
In the procedure of hot dip galvanizing, when pure zinc plated without other alloying additions, the corrosion resistance of zinc coating is poor, meanwhile the bath surface will produce a number of zinc dross, zinc ash, and this phenomenon will cause a waste of zinc, resulting in an increase in product costs, and the surface of product is relatively dark, the brightness is not enough, whilst sometimes even form a phenomenon of the formation of the Pan-color on the surface of the galvanized parts.
Table 1 Al and RE on the plating properties of the preliminary study Al% RE% 0 1 2 3 0 Coating quality No leakage, the best smoothness, poor brightness Extremely small and scattered leakages, better smoothness, the best brightness Extremely small and scattered leakages, general smoothness, convex small grains on surface, the best brightness The most leakages which affecting the resist-corrosion of plates, the poorest smoothness, uneven surface, the best brightness Average corrosion rate[g/mm2·h] 0.6743 0.80028 0.75924 1.38124 0.5 Coating quality No leakage, better smoothness, the best brightness Slightly big and scattered leakages, general smoothness, Some rough on one side, the best brightness More leakages, general smoothness, the best brightness More leakages, the poorest smoothness, uneven surface, the best brightness Average corrosion rate[g/mm2·h] 0.56618 0.7357 0.79648 2.80494 1 Coating quality No leakage, better smoothness, the best brightness Extremely small and scattered leakages
Table 2 Al and RE on the plating properties of the fine study RE% Al% 0.25 0. 5 0.75 1 0.5 Coating quality No leakage, good, smoothness, slightly convex small grains on surface, good brightness No leakage, good smoothness, slightly convex small grains on surface, good brightness No leakage, good smoothness, slightly convex small grains on surface, good brightness Extremely small and scattered leakages, good smoothness, slightly convex small grains on surface, good brightness Average corrosion rate[g/mm2·h] 0.5599 0.55922 0.44666 0.67918 1 Coating quality No leakage, good smoothness, slightly convex small grains on surface, good brightness No leakage, good smoothness, slightly convex small grains on surface, good brightness No leakage, good smoothness, slightly convex small grains on surface, good brightness No leakage, good smoothness, slightly convex small grains on surface, good brightness Average corrosion rate[g/mm2·h] 0.38092 0.47136 0.61802 0.45456 1.5 Coating quality Extremely
small and scattered leakages, good smoothness, slightly convex small grains on surface, good brightness No leakage, good smoothness, slightly convex small grains on surface, good brightness No leakage, good smoothness, slightly convex small grains on surface, good brightness No leakage, good smoothness, slightly convex small grains on surface, good brightness Average corrosion rate[g/mm2·h] 0.35098 0.35138 0.46402 0.46892 In this set of experiments, the plated parts had no leakage and the surface quality were rather good, the overall surface quality was relatively better comparing with the last group.
Pure zinc ingot after hot dip galvanized Alloy ingot after hot dip galvanized Fig.2 Comparison of Zinc ingot appearance in hot dip galvanizing process between pure zine ingot and alloy ingot consist of Zn, Al and RE When plating pure zinc, in the hot dip process, the surface of zinc bath will produce in a large number of zinc ash, just as shown in Fig. 2 and produce very fast, causing a huge waste of zinc, but after adding the alloying elements, the speed and volume of the zinc cash which were formed on the surface of zinc bath significantly reduced, greatly increasing the utilization rate of zinc, reduce the cost of production; when plating pure zinc parts and the surface of the plated parts’ brightness is not enough, sometimes even generate Pan-color, adding alloying elements has an apparent improvement towards this phenomenon.
Table 1 Al and RE on the plating properties of the preliminary study Al% RE% 0 1 2 3 0 Coating quality No leakage, the best smoothness, poor brightness Extremely small and scattered leakages, better smoothness, the best brightness Extremely small and scattered leakages, general smoothness, convex small grains on surface, the best brightness The most leakages which affecting the resist-corrosion of plates, the poorest smoothness, uneven surface, the best brightness Average corrosion rate[g/mm2·h] 0.6743 0.80028 0.75924 1.38124 0.5 Coating quality No leakage, better smoothness, the best brightness Slightly big and scattered leakages, general smoothness, Some rough on one side, the best brightness More leakages, general smoothness, the best brightness More leakages, the poorest smoothness, uneven surface, the best brightness Average corrosion rate[g/mm2·h] 0.56618 0.7357 0.79648 2.80494 1 Coating quality No leakage, better smoothness, the best brightness Extremely small and scattered leakages
Table 2 Al and RE on the plating properties of the fine study RE% Al% 0.25 0. 5 0.75 1 0.5 Coating quality No leakage, good, smoothness, slightly convex small grains on surface, good brightness No leakage, good smoothness, slightly convex small grains on surface, good brightness No leakage, good smoothness, slightly convex small grains on surface, good brightness Extremely small and scattered leakages, good smoothness, slightly convex small grains on surface, good brightness Average corrosion rate[g/mm2·h] 0.5599 0.55922 0.44666 0.67918 1 Coating quality No leakage, good smoothness, slightly convex small grains on surface, good brightness No leakage, good smoothness, slightly convex small grains on surface, good brightness No leakage, good smoothness, slightly convex small grains on surface, good brightness No leakage, good smoothness, slightly convex small grains on surface, good brightness Average corrosion rate[g/mm2·h] 0.38092 0.47136 0.61802 0.45456 1.5 Coating quality Extremely
small and scattered leakages, good smoothness, slightly convex small grains on surface, good brightness No leakage, good smoothness, slightly convex small grains on surface, good brightness No leakage, good smoothness, slightly convex small grains on surface, good brightness No leakage, good smoothness, slightly convex small grains on surface, good brightness Average corrosion rate[g/mm2·h] 0.35098 0.35138 0.46402 0.46892 In this set of experiments, the plated parts had no leakage and the surface quality were rather good, the overall surface quality was relatively better comparing with the last group.
Pure zinc ingot after hot dip galvanized Alloy ingot after hot dip galvanized Fig.2 Comparison of Zinc ingot appearance in hot dip galvanizing process between pure zine ingot and alloy ingot consist of Zn, Al and RE When plating pure zinc, in the hot dip process, the surface of zinc bath will produce in a large number of zinc ash, just as shown in Fig. 2 and produce very fast, causing a huge waste of zinc, but after adding the alloying elements, the speed and volume of the zinc cash which were formed on the surface of zinc bath significantly reduced, greatly increasing the utilization rate of zinc, reduce the cost of production; when plating pure zinc parts and the surface of the plated parts’ brightness is not enough, sometimes even generate Pan-color, adding alloying elements has an apparent improvement towards this phenomenon.
Online since: July 2014
Authors: Qing Xue, Yin Qun Hua, Zhen Rong, Rui Fang Chen, Yu Chuan Bai
The microstructure was characterized by highly tangled and dense dislocations and a large number of twins.
And the grain is refined owing to the dynamic recrystallization.
Meanwhile, a larger number of microstructure defects, such as dislocation and twins, are induced on the surface layer.
Fig.1 (b) is a lager number of typical mechanical twins.
The corrosion layer has a good adherence with the substrate and the grains are tiny homogeneous.
And the grain is refined owing to the dynamic recrystallization.
Meanwhile, a larger number of microstructure defects, such as dislocation and twins, are induced on the surface layer.
Fig.1 (b) is a lager number of typical mechanical twins.
The corrosion layer has a good adherence with the substrate and the grains are tiny homogeneous.
Online since: March 2008
Authors: C.H. Hu, Shi Ning Ma, Nai Shu Zhu, C.Q. Li
Some
CTBN grains which splited from the base resin can form deformation micropores.
Some grains pined in the front or middle of the crack.
Appearance of rubber particles translated from grain to "island" in adhesive with 4wt% nano- SiO2.
Appearance of rubber particles translated from grain to"island" in adhesive with 4wt% nano- SiO2.
Absorption Wave Number/cm -1 Absorption Absorption Wave Number/cm -1 Wave Number/cm -1 Wave Number/cm -1 (a) (b) (c) (d) Absorption
Some grains pined in the front or middle of the crack.
Appearance of rubber particles translated from grain to "island" in adhesive with 4wt% nano- SiO2.
Appearance of rubber particles translated from grain to"island" in adhesive with 4wt% nano- SiO2.
Absorption Wave Number/cm -1 Absorption Absorption Wave Number/cm -1 Wave Number/cm -1 Wave Number/cm -1 (a) (b) (c) (d) Absorption
Online since: February 2011
Authors: Hong Yu Chen, Long Chuan Dou, Hui Wang, Wei Zhang, Ai Ju Li
It was found that the addition Sn acts as grain coarser, but Se acts as grain refiner and Pb-Sn-Se alloys feature smaller grains.
The results indicated that the addition of Sn to Pb-Sn alloys resulted from grain coarsening, however, alloys containing Se feature smaller grains and selenium acted as grain refiner.
Smaller grain would probably reduce the intergranular corrosion sensibility.
Conclusions Lead base alloys containing Se feature smaller grains and selenium acts as grain refiner.
Number of the research funding project is 9151063101000052.
The results indicated that the addition of Sn to Pb-Sn alloys resulted from grain coarsening, however, alloys containing Se feature smaller grains and selenium acted as grain refiner.
Smaller grain would probably reduce the intergranular corrosion sensibility.
Conclusions Lead base alloys containing Se feature smaller grains and selenium acts as grain refiner.
Number of the research funding project is 9151063101000052.
Online since: September 2007
Authors: Alan F. Jankowski
Each layer
pair of the A/B multilayer is designed to have a specific integral number (n,m) of atomic planes, i.e.
For example, the energy dispersive x-ray spectra of the free standing foils reveal the characteristic Cu L, and Au M x-ray peaks that are used to quantify the composition as determined from the atomic number (Z)- absorption (A)-fluorescence (F) semi-quantitative analysis.
Grain size.
Diffusion Models Grain boundary.
Thus, the change in grain size (∆dg) with anneal time is, [∆dg]2 = [dg(f)]2 - [dg(i)] 2 (3) where dg(i) is the as-deposited grain size and dg(f) is the final grain size.
For example, the energy dispersive x-ray spectra of the free standing foils reveal the characteristic Cu L, and Au M x-ray peaks that are used to quantify the composition as determined from the atomic number (Z)- absorption (A)-fluorescence (F) semi-quantitative analysis.
Grain size.
Diffusion Models Grain boundary.
Thus, the change in grain size (∆dg) with anneal time is, [∆dg]2 = [dg(f)]2 - [dg(i)] 2 (3) where dg(i) is the as-deposited grain size and dg(f) is the final grain size.
Online since: August 2009
Authors: Jian Zhong Wang, Li Jia He, Jin Gang Qi, Bing Wang, Hui Ling Du
The modification of liquid metal by electric pulse (EP, EPM) is a novel method for grain
refinement.
The decrease of modifying time could result in an obvious weaker principal peak in structure factor curve compared with the optimal EP technique parameters, but a slight increase of coordination number (�s), correlation radius (rc) and average atom number per cluster (�at) is still observed under this condition.
These facts indicate that the EP-modified liquid aluminum could gain an increasing order degree, and thus have an advantage during the formation of a stable nucleus, eventually leading to a grain-refining solidification structure.
The advent of electric pulse modification (EPM) had a significant impact on the development of grain refining techniques and led a growing interest in liquid metal controls for researchers, as it was generally accepted that the EPM effects rooted from a certain structural change of liquid metal[5].
Structural parameters EPM1 EPM2 Unmodified Atomic density 0.0529 0.0529 0.0531 Correlation radius (rc)[nm] 0.925 0.805 0.780 Average atom number per cluster (�at) 174 131 119 Coordinating number (�s) 9.063 8.566 8.546 The nearest neighbor distance (r1)[nm] 0.285 0.285 0.285 It is shown in Table 1 that the rc value increases from 0.780nm (the unmodified) to 0.805nm (EPM2), even to 0.925 (EPM1) and the r1 value is a constant of 0.285nm, at the same time, the value of �at ranges from 119 (the unmodified) up to 131 (EPM2), even to 174 (EPM1).
The decrease of modifying time could result in an obvious weaker principal peak in structure factor curve compared with the optimal EP technique parameters, but a slight increase of coordination number (�s), correlation radius (rc) and average atom number per cluster (�at) is still observed under this condition.
These facts indicate that the EP-modified liquid aluminum could gain an increasing order degree, and thus have an advantage during the formation of a stable nucleus, eventually leading to a grain-refining solidification structure.
The advent of electric pulse modification (EPM) had a significant impact on the development of grain refining techniques and led a growing interest in liquid metal controls for researchers, as it was generally accepted that the EPM effects rooted from a certain structural change of liquid metal[5].
Structural parameters EPM1 EPM2 Unmodified Atomic density 0.0529 0.0529 0.0531 Correlation radius (rc)[nm] 0.925 0.805 0.780 Average atom number per cluster (�at) 174 131 119 Coordinating number (�s) 9.063 8.566 8.546 The nearest neighbor distance (r1)[nm] 0.285 0.285 0.285 It is shown in Table 1 that the rc value increases from 0.780nm (the unmodified) to 0.805nm (EPM2), even to 0.925 (EPM1) and the r1 value is a constant of 0.285nm, at the same time, the value of �at ranges from 119 (the unmodified) up to 131 (EPM2), even to 174 (EPM1).
Online since: December 2007
Authors: Hans-Jürgen Christ, Claus Peter Fritzen, Helge Knobbe, Olaf Düber, Philipp Köster, Boris Künkler, Ulrich Krupp
., high-cycle
fatigue (HCF), is mostly based on S/N diagrams in the range of the conventional fatigue limit, for
carbon steels mostly correlated with a critical number of cycles of NFL=2⋅106.
Hence, the fatigue life can be finite even for loading cases below the fatigue limit and for number of cycles being orders of magnitude higher than 10 6.
This is in contradiction to the work of Chai [8,9], who observed plastic deformation limited to the α grains.
The slip bands (Fig. 1a) seem not to be able to overcome the adjacent grain and phase boundaries.
The results of the EBSD measurements were used to assign crystallographic orientations to each individual grain.
Hence, the fatigue life can be finite even for loading cases below the fatigue limit and for number of cycles being orders of magnitude higher than 10 6.
This is in contradiction to the work of Chai [8,9], who observed plastic deformation limited to the α grains.
The slip bands (Fig. 1a) seem not to be able to overcome the adjacent grain and phase boundaries.
The results of the EBSD measurements were used to assign crystallographic orientations to each individual grain.
Online since: September 2011
Authors: Jing Yu Mo, Jian Hua Sui, Fang Xiong
The weave grain will be less clarity as the increase of fabric voidage.
For example, general fabrics all emphasize clear texture and the obvious grain-land boundary in jacquard products is always highlighted.
For twisting, the number and direction of the twist are also various.
Some fabrics can form indistinct stripes or checks effect by taking advantage of the differences in denier, number and direction of twist, shrinkage of material and weave, interwoven density, etc.
l When configured with the same surface pattern and in the opposite direction, it will completely destroy the original pattern and form a new texture; l Plain weave with the same surface can reduce the clarity of the grain boundary and make the texture vague and implicit.
For example, general fabrics all emphasize clear texture and the obvious grain-land boundary in jacquard products is always highlighted.
For twisting, the number and direction of the twist are also various.
Some fabrics can form indistinct stripes or checks effect by taking advantage of the differences in denier, number and direction of twist, shrinkage of material and weave, interwoven density, etc.
l When configured with the same surface pattern and in the opposite direction, it will completely destroy the original pattern and form a new texture; l Plain weave with the same surface can reduce the clarity of the grain boundary and make the texture vague and implicit.
Online since: May 2019
Authors: Wen Quan Wang, Wei Jian Liu, Fan Jiang
The HAZ was affected by thermal stress, the grain grew slightly, but less than the base metal grains size, where were enlarge by the heat from weld.
Grains of NZ at Cu side are fine, so microhardness increased sharply.
Since the grains of TMAZ and HAZ are also smaller than the grains size of BM, the microhardness shows a decreasing trend from NZ to BM.
In Fig. 7(b), there are a large number of dimples on the fracture surface.
According to the study by Xu et al [10], the surfaces of dimples are rough with a number of plastic deformation and tearing ridges.
Grains of NZ at Cu side are fine, so microhardness increased sharply.
Since the grains of TMAZ and HAZ are also smaller than the grains size of BM, the microhardness shows a decreasing trend from NZ to BM.
In Fig. 7(b), there are a large number of dimples on the fracture surface.
According to the study by Xu et al [10], the surfaces of dimples are rough with a number of plastic deformation and tearing ridges.