The superior thermal stability and irradiation resistance capacities of tungsten composites synthesized by simple second-phase particle component modulation

2022 ◽  
pp. 153522
Author(s):  
Gang Yao ◽  
Hong–Yu Chen ◽  
Zhi-Hao Zhao ◽  
Lai-Ma Luo ◽  
Yong Ma ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Phase Particle ◽  
Second Phase ◽  
Irradiation Resistance

scholarly journals Recycled ceramic composite for automobile brake pad application

2018 ◽  
Vol 39 (1) ◽  
pp. 35-46 ◽  
Author(s):  
Johnson O. Agunsoye ◽  
Sefiu. A. Bello ◽  
Adeola A. Bamigbaiye ◽  
Kayode A. Odunmosu ◽  
Isaac O. Akinboye
Keyword(s):  
Thermal Stability ◽  
Spatial Configuration ◽  
Phase Particle ◽  
Steel Slag ◽  
Second Phase ◽  
Brake Pad ◽  
Friction Property ◽  
Wear Rates ◽  
Brake Pads ◽  
Commercial Grade

Abstract Ceramic tile/steel slag-graphite-Arabic gum composite has been developed using conventional casting techniques for brake pad applications. Chemical properties of the phases present in the matrix of the developed composite were examined using X-ray diffractometer. Spatial configuration of the phases was viewed using Scanning Electron Microscope. Wear and thermal properties of the developed composite were also investigated. Correlation between the properties of the developed composite and the commercial grade brake pads were made. Results showed partial homogenity of the second phase particle within the ceramic matrix. The developed composite brake pad showed a better friction property than the commercial grade brake pads up to 200 s while above this duration, the reverse was the case. The developed composite brake displayed lower wear rates and better thermal stability than the commercial grades implying optimum combination of good wear resistance, friction property and thermal stability up to 200 s. Since brake application while driving is an intermittent short span process (< 3 minutes), the developed composite could serve as a replacement for asbestos brake pad for automobile applications.

Diffusional relaxation around a second phase particle

1980 ◽  
Vol 28 (3) ◽  
pp. 319-325 ◽  
Author(s):  
T. Mori ◽  
M. Okabe ◽  
T. Mura
Keyword(s):  
Phase Particle ◽  
Second Phase ◽  
Diffusional Relaxation

scholarly journals Grain Refinement by Second Phase Particles under Applied Stress in ZK60 Mg Alloy with Y through Phase Field Simulation

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1903 ◽  
Author(s):  
Yuhao Song ◽  
Mingtao Wang ◽  
Yaping Zong ◽  
Ri He ◽  
Jianfeng Jin
Keyword(s):  
Grain Refinement ◽  
Applied Stress ◽  
Phase Field ◽  
Phase Particle ◽  
Alloy System ◽  
Second Phase ◽  
Recrystallization Process ◽  
Time Space ◽  
Second Phase Particles ◽  
Zk60 Alloy

Based on the principle of grain refinement caused by the second-phase particles, a phase field model was built to describe the recrystallization process in the ZK60 alloy system with Y added under applied stress between temperatures 573 and 673 K for 140 min duration. The simulation of grain growth with second phase particles and applied stress during annealing process on industrial scale on the condition of real time-space was achieved. Quantitative analysis was carried out and some useful laws were revealed in ZK60 alloy system. The second phase particles had a promoting effect on the grain refinement, however the effect weakened significantly when the content exceeded 1.5%. Our simulation results reveal the existence of a critical range of second phase particle size of 0.3–0.4 μm, within which a microstructure of fine grains can be obtained. Applied stress increased the grain coarsening rate significantly when the stress was more than 135 MPa. The critical size of the second phase particles was 0.4–0.75 μm when the applied stress was 135 MPa. Finally, a microstructure with a grain size of 11.8–13.8 μm on average could be obtained when the second phase particles had a content of 1.5% and a size of 0.4–0.75 μm with an applied stress less than 135 Mpa after 30 min annealing at 573 K.

Effect of Rare Earth (RE) La on Solid Solution of Second Phase Particle and Austenite Grain Growth in Steel Containing High Niobium

2011 ◽  
Vol 189-193 ◽  
pp. 2869-2874 ◽  
Author(s):  
Wen Zhong Song ◽  
Qi Fang ◽  
Hui Ping Ren ◽  
Zi Li Jin ◽  
Hui Chang
Keyword(s):  
Solid Solution ◽  
Growth Rate ◽  
Rare Earth ◽  
Grain Growth ◽  
Phase Particle ◽  
Solution Temperature ◽  
Second Phase ◽  
Austenite Grain ◽  
Austenite Grain Growth ◽  
Soaking Temperature

The solid solution of the second phase particle and austenite grain growth behavior of the high niobium-containing RE steel was studied by mathematical calculation and extraction replica technique. The purpose of the study was to investigate the effects of Rare Earth La on austenite grain growth and propose an empirical equation for predicting the austenite grain size of RE steel. Austenite grain grows in an exponential law with the increase of heating temperature, while approximately in a parabolic law with the increase of holding time. Results show that the RE steel has good anti-coarsening ability at elevated temperatures. When soaking temperature is lower than 1250°C , AGS and growth rate are small for high niobium steel, but soaking temperature is lower than 1220°C , AGS and growth rate are small for RE steel. RE La can promote solid solution of second-phase particles Nb(C, N), the solution temperature decrease 30°C than high niobium steel.

Effect of Nanometer Magnesium Oxide Addition on the Cast Microstructure of X80 Pipeline Steel

2013 ◽  
Vol 401-403 ◽  
pp. 610-613
Author(s):  
Jian Ming Wang ◽  
Yang Liu ◽  
Yan Liu ◽  
Qian He Ma
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Magnesium Oxide ◽  
Pipeline Steel ◽  
Harsh Environment ◽  
Second Phase ◽  
X80 Pipeline Steel ◽  
Oxide Addition ◽  
Second Phase Particles ◽  
Cast Microstructure

The pipeline steel as an application in pipeline construction must have good comprehensive mechanical properties due to the harsh environment of the pipeline engineering. So this experiment takes the X80 pipeline steel as the research object, the thermal stability second phase particles which would not be dissolved or aggregated at high temperature will be expected by means of adding nanomagnesium oxide into the steel with the method of carrier dispersion addition. The effect of nanometer magnesium oxide addition on the cast microstructure of X80 pipeline steel was analysed. The results show that the cast microstructure is consist of the ferrite and a small amount bainite. And the bainite is distributed at the boundary of the ferrite grains. When adding 0.02 wt% nanometer magnesium oxides, the number of bainite increases significantly in the cast microstructure, which is mostly distributed at the boundary of the ferrite grains.

Functional Gradation in Precipitation Hardenable AA7075 Alloy by Differential Cooling Strategies

2021 ◽  
Vol 883 ◽  
pp. 159-166
Author(s):  
Emad Scharifi ◽  
Moritz Roscher ◽  
Steffen Lotz ◽  
Ursula Weidig ◽  
Eric Jägle ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Phase Particle ◽  
Hot Stamping ◽  
Aging Treatment ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Material Strength ◽  
Second Phase ◽  
Contrast Imaging ◽  
Forming Tools

Inspired by steel forming strategies, this study focuses on the effect of differential cooling on mechanical properties and precipitation kinetics during hot stamping of high strength AA7075 alloy. For this aim, different forming strategies were performed using segmented and differentially heated forming tools to provide locally tailored microstructures. Upon processing, uniaxial tensile tests and hardness measurements were used to characterize the mechanical properties after the aging treatment. Microstructure investigations were conducted to examine the strengthening mechanisms using the electron channeling contrast imaging (ECCI) technique in a scanning electron microscope (SEM). Based on the obtained results, it can be deduced that the tool temperatures play a key role in influencing the mechanical properties. Lower tool temperatures result in higher material strength and higher tool temperatures in lower mechanical properties. By changing the cooling rate with the use of differently heated forming tools, the mechanical properties can be controlled. Microstructure investigations revealed the formation of very fine and homogeneously distributed particles at cooled zones, which were associated with elevated mechanical properties due to the suppression of second phase particle formation during cooling. In contrast, coarse particles were observed at lower cooling rates, explaining the lower material strength found in these zones.

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