Seminar on modern electrothermal equipment for heat-treating metallic materials

1979 ◽  
Vol 21 (7) ◽  
pp. 561-563
Author(s):  
M. B. Gutman ◽  
N. F. Shur
Keyword(s):  
Heat Treating ◽  
Metallic Materials ◽  
Electrothermal Equipment

Microstructure and Phase Transformation of Super-High Pressure Mg-Li Alloy

2015 ◽  
Vol 816 ◽  
pp. 375-380 ◽  
Author(s):  
Qiu Ming Peng ◽  
Hui Fu ◽  
Yan An Wang ◽  
Hui Li
Keyword(s):  
High Pressure ◽  
Phase Transformation ◽  
Heat Treating ◽  
Dendritic Morphology ◽  
Metallic Materials ◽  
Cast Sample ◽  
Temperature Range ◽  
Electronic Distribution ◽  
Heat Treated ◽  
Dislocation Movement

Super-high pressure (SHP) changes crystal structure and electronic distribution of metallic materials, which plays an important role in properties. Herein, a duplex Mg-7%wt.Li alloy was heat-treated under SHP (2 GPa) by cubic-anvil large-volume press with six rams for 2 h in the temperature range of 450~1350 °C. Microstructure, phase transformation behavior and mechanical properties were examined. Compared with the as-cast sample, the SHP samples after heat-treating from 450 °C to 750 °C under 2 GPa were composed of twinning in addition to duplex structure. Comparatively, the samples treated between 1050 °C and 1350 °C exhibit typical dendritic morphology. Phase transformation from Li3Mg7 phase or Li0.92Mg4.08 phase to Li3Mg17 phase occurred during the whole investigated temperature range, in which only the Li3Mg17 phase maintained when the temperature exceeds 1050 °C. The microhardness of the sample prepared at 750 °C under 2 GPa was 73.15HV, which is 1.5 times higher than that of the as-cast one. The improved microhardness is mainly attributed to the formation of nanosized twins during SHP treatment. These fine twins effectively prohibit the dislocation movement during deformation. It reveals the SHP is an effective approach to prepare high performation Mg alloys.

SEM Examination of a Used Diamond Knife

1971 ◽  
Vol 29 ◽  
pp. 452-453
Author(s):  
J. Temple Black
Keyword(s):  
Electron Microscope ◽  
High Voltage ◽  
High Magnification ◽  
Metallic Materials ◽  
Wide Spread ◽  
Thin Sections ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Scanning Electron ◽  
Diamond Knife

Since its introduction by Fernandez-Moran, the diamond knife has gained wide spread usage as a common material for cutting of thin sections of biological and metallic materials into thin films for examination in the transmission electron microscope. With the development of high voltage E.M. and scanning transmission E.M., microtomy applications will become increasingly important in the preparation of specimens. For those who can afford it, the diamond knife will thus continue to be an important tool to accomplish this effort until a cheaper but equally strong and sharp tool is found to replace the diamond, glass not withstanding.In Figs. 1 thru 3, a first attempt was made to examine the edge of a used (β=45°) diamond knife by means of the scanning electron microscope. Because diamond is conductive, first examination was tried without any coating of the diamond. However, the contamination at the edge caused severe charging during imaging. Next, a thin layer of carbon was deposited but charging was still extensive at high magnification - high voltage settings. Finally, the knife was given a light coating of gold-palladium which eliminated the charging and allowed high magnification micrographs to be made with reasonable resolution.

Observation of secondary slip systems in tungsten bicrystals

1984 ◽  
Vol 42 ◽  
pp. 478-479
Author(s):  
J. R. Fekete ◽  
R. Gibala
Keyword(s):  
Stress Field ◽  
Grain Boundaries ◽  
Deformation Behavior ◽  
Stress Axis ◽  
Polycrystalline Materials ◽  
Slip Systems ◽  
Metallic Materials ◽  
Twist Boundary ◽  
Secondary Slip ◽  
Plane Normal

The deformation behavior of metallic materials is modified by the presence of grain boundaries. When polycrystalline materials are deformed, additional stresses over and above those externally imposed on the material are induced. These stresses result from the constraint of the grain boundaries on the deformation of incompatible grains. This incompatibility can be elastic or plastic in nature. One of the mechanisms by which these stresses can be relieved is the activation of secondary slip systems. Secondary slip systems have been shown to relieve elastic and plastic compatibility stresses. The deformation of tungsten bicrystals is interesting, due to the elastic isotropy of the material, which implies that the entire compatibility stress field will exist due to plastic incompatibility. The work described here shows TEM observations of the activation of secondary slip in tungsten bicrystals with a [110] twist boundary oriented with the plane normal parallel to the stress axis.

Microstructural aspects of spalling for hard metallic materials

2000 ◽  
Vol 10 (PR9) ◽  
pp. Pr9-641-Pr9-646
Author(s):  
P. Chevrier ◽  
J. R. Klepaczko
Keyword(s):  
Metallic Materials

On standardization of the plate impact experiment for polymeric and metallic materials

2006 ◽  
Vol 134 ◽  
pp. 583-589
Author(s):  
Y. Sato ◽  
K. Nishimura
Keyword(s):  
Metallic Materials ◽  
Plate Impact ◽  
Impact Experiment

Comparing fast inductive tempering and conventional tempering: Effects on microstructure and mechanical properties

2018 ◽  
Vol 115 (4) ◽  
pp. 407 ◽  
Author(s):  
Annika Eggbauer Vieweg ◽  
Gerald Ressel ◽  
Peter Raninger ◽  
Petri Prevedel ◽  
Stefan Marsoner ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Impact Energy ◽  
Charpy Impact ◽  
Heat Treating ◽  
Processing Route ◽  
High Heating Rate ◽  
Heating Rates ◽  
High Heating ◽  
Tempering Treatment ◽  
Carbide Distribution

Induction heating processes are of rising interest within the heat treating industry. Using inductive tempering, a lot of production time can be saved compared to a conventional tempering treatment. However, it is not completely understood how fast inductive processes influence the quenched and tempered microstructure and the corresponding mechanical properties. The aim of this work is to highlight differences between inductive and conventional tempering processes and to suggest a possible processing route which results in optimized microstructures, as well as desirable mechanical properties. Therefore, the present work evaluates the influencing factors of high heating rates to tempering temperatures on the microstructure as well as hardness and Charpy impact energy. To this end, after quenching a 50CrMo4 steel three different induction tempering processes are carried out and the resulting properties are subsequently compared to a conventional tempering process. The results indicate that notch impact energy raises with increasing heating rates to tempering when realizing the same hardness of the samples. The positive effect of high heating rate on toughness is traced back to smaller carbide sizes, as well as smaller carbide spacing and more uniform carbide distribution over the sample.

Effect of Foot-and-Mouth Disease Disinfectant on Corrosion of Metallic Materials

2013 ◽  
Vol 51 (4) ◽  
pp. 265-273
Author(s):  
YoungSik Kim ◽  
MinCheol Shin
Keyword(s):  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Metallic Materials ◽  
Foot And Mouth
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