全文获取类型
收费全文 | 53篇 |
免费 | 2篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 8篇 |
金属工艺 | 4篇 |
轻工业 | 2篇 |
无线电 | 5篇 |
一般工业技术 | 10篇 |
冶金工业 | 16篇 |
原子能技术 | 1篇 |
自动化技术 | 7篇 |
出版年
2022年 | 1篇 |
2021年 | 1篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2015年 | 2篇 |
2013年 | 5篇 |
2012年 | 2篇 |
2011年 | 1篇 |
2010年 | 1篇 |
2009年 | 1篇 |
2008年 | 1篇 |
2006年 | 2篇 |
2005年 | 1篇 |
2003年 | 1篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1981年 | 1篇 |
1979年 | 2篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1973年 | 3篇 |
1972年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有55条查询结果,搜索用时 15 毫秒
1.
The concentration of zinc and magnesium across grain boundaries was measured by means of an electron probe microanalyzer for
an Ag-Zn-Mg alloy after different quenching (brine, water, oil, and air) and aging heat treatments (room temperature, 165°,
and 200°C). Significant solute segregation was detected in quenched specimens and also in specimens that were aged at room
temperature. While no solute enrichment was measured in specimens that were aged at elevated temperatures, solute depletion
was observed in a considerable proportion of the examined boundaries. It was concluded that solute segregation to grain boundaries
occurred during quenching and was relieved during aging.
C. R. SHASTRY, Formerly Graduate Research Assistant at Rens-selaer Polytechnic Institute, Troy, N. Y. 相似文献
2.
The effect of quench rate and boundary type on the width of precipitate-free zones in an Al-6.86 wt pct Zn-2.35 wt pct Mg
alloy that was aged at two different temperatures was studied by transmission electron microscopy. The width of the precipitate-free
zones increased with decreasing quench rate, but by a considerably smaller extent than that predicted from calculations using
previous models based upon quenched vacancy profiles. The simple tilt-type boundaries were associated, in general, with narrower
precipitate-free zones than those occurring at complex-type boundaries. The width of precipitate-free zones was also observed
to decrease with increasing precipitate coverage in the boundary. A mechanism of precipitate-free zone formation based on
the modification of the as-quenched vacancy profile by the vacancies generated due to grain boundary precipitation was proposed
to explain the observed results.
C. R. SHASTRY, formerly Graduate Student, Materials Division, Rensselaer Polytechnic Institute, Troy. N. Y. 相似文献
3.
4.
B Sriram Shastry 《Bulletin of Materials Science》1979,1(3-4):195-199
The remarkable remanence effects observed in spin glasses are discussed. Some theoretical approaches and results are reviewed.
Invited talk given at the Indian Academy of Sciences, Bangalore, Academy discussion meeting on phase transitions, June 21st,
1978. 相似文献
5.
6.
The stress concentration factor K in a tensile strip with large circular hole is accurately determined using a high precision, plane stress, triangular element. The values of a/w where a is the diameter of the hole and w is the width of the strip, considered range from 0.99 to 0.999. The values of K obtained found to be very near to but greater than 2.0, when linear analysis is performed. Some discrepancies in the stress values at the outer free edge observed in the present linear analysis compared to the well documented experimental values prompted the authors to go for geometrically nonlinear analysis gave a K value which is a function of the load applied, less than 2.0 and for sufficiently large loads this value is very near but slightly greater than 1.0. 相似文献
7.
The effect of heat treatment on the relative amounts of magnesium, zinc, copper, iron and silicon in grain boundaries of aluminum
7075 alloy was investigated with Auger electron spectroscopy in a scanning Auger microprobe. It was observed that both aging
and solution treatments affect the distribution of these elements at grain boundaries. If identical solution heat treatments
were employed, the aging treatment determined the solute distribution at the grain boundaries, and for fixed final aging treatment,
the temperature of solution anneal determined the solute distribution. Among specimens given a T6 final aging treatment (24
h at 394 K (250 °F)) with prior solution treatment temperatures in the 666 K (740 °F) to 800 K (980 °F) range, 711 K (820
°F) solution treated specimen was found to have the least solute concentration at grain boundaries. The observed behavior
is explained on the basis of equilibrium and nonequilibrium segregation of solute elements to grain boundaries occurring on
quenching and during aging. 相似文献
8.
Distribution of aluminum in hot-dip galvanized coatings 总被引:2,自引:0,他引:2
Valdemar Furdanowicz C. Ramadeva Shastry 《Metallurgical and Materials Transactions A》1999,30(12):3031-3044
Hot-dip galvanized panels of low-carbon (LC) and interstitial-free (IF) steels were produced in a laboratory simulator with
an average coating mass of 60 g/m2. Three pot aluminum levels were used, viz., 0.10 pct (by wt), 0.15 pct, and 0.18 pct. Metallography, scanning electron microscopy (SEM), and transmission electron microscopy
(TEM) were used to characterize coating and base steel microstructures. Wet chemical analysis and scanning transmission electron
microscopy (STEM) were employed for compositional analyses. The aluminum content of the melt was found to be the predominant
factor influencing the distribution of Al in the coating. At 0.18 pct melt aluminum, Al is partitioned between the aluminide
inhibition layer at the coating-steel interface (∼80 pct) and the zinc overlay (∼20 pct). At 0.15 pct, it is partitioned among
the aluminide layer (∼75 pct to 80 pct), zinc-iron (FeZn13, ζ) intermetallic layer (∼5 pct to 15 pct), and the coating overlay (∼10 pct). At 0.10 pct, the aluminum is divided almost equally
between the overlay and the zinc-iron intermetallics. At the two lower aluminum levels is the distribution marginally influenced
by the steel grade. The ζ was found to not preferentially nucleate at the ferrite grain boundaries. When both the aluminide and ζ occurred at the coating-steel interface, the ζ particles appeared near discontinuities and thinner regions in the aluminide layer. The coating, relative to the melt, is
enriched in aluminum because of its concentration in the aluminide and in the zinc-iron intermetallics. This enrichment increases
with melt aluminum through an increase in the aluminum content of the aluminide layer and not of its thickness. In addition,
a few tens-of-nanometers-thick layer enriched in aluminum, oxygen, and iron is observed on the outer surface of all coatings.
The aluminum content in this layer also increases with an increase in the melt aluminum, but it contributes negligibly to
the coatings’s content because of its extreme thinness. 相似文献
9.
10.
The nanoindentation technique can be employed in shape memory alloys (SMAs) to discern the transformation temperatures as well as to characterize their mechanical behavior. In this paper, we use it with simultaneous measurements of the mechanical and the electrical contact resistances (ECR) at room temperature to probe two SMAs: austenite (RTA) and martensite (RTM). Two different types of indenter tips – Berkovich and spherical – are employed to examine the SMAs’ indentation responses as a function of the representative strain, εR. In Berkovich indentation, because of the sharp nature of the tip, and in consequence the high levels of strain imposed, discerning the two SMAs on the basis of the indentation response alone is difficult. In the case of the spherical tip, εR is systematically varied and its effect on the depth recovery ratio, ηd, is examined. Results indicate that RTA has higher ηd than RTM, but the difference decreases with increasing εR such that ηd values for both the alloys would be similar in the fully plastic regime. The experimental trends in ηd vs. εR for both the alloys could be described well with a ηd ∝ (εR)?1 type equation, which is developed on the basis of a phenomenological model. This fit, in turn, directs us to the maximum εR, below which plasticity underneath the indenter would not mask the differences in the two SMAs. It was demonstrated that the ECR measurements complement the mechanical measurements in demarcating the reverse transformation from martensite to austenite during unloading of RTA, wherein a marked increase in the voltage was noted. A correlation between recovery due to reverse transformation during unloading and increase in voltage (and hence the electrical resistance) was found. 相似文献