Analysis of Cooling Curves, Microstructure and Properties of Chill Cast Al-B4C Composites

2015 ◽  
Vol 1101 ◽  
pp. 32-35 ◽  
Author(s):  
K.V. Sreenivas Rao ◽  
S. Sanman
Keyword(s):  
Cooling Rate ◽  
Die Casting ◽  
Mold Material ◽  
Cooling Curves ◽  
Test Results ◽  
Micro Hardness ◽  
Turn On ◽  
Chill Cast ◽  
Particulate Distribution ◽  
Optical Micrographs

The cooling rate depends on the properties of the mold material which has significant influence on the formation of microstructure and in turn on the properties of the cast components. This work is aimed at preparing the Al-B4C composite using different chill materials by gravity die casting and recording the casting temperature during pouring and subsequent solidification to analyze the cooling rate of the casting. The effect of chilling on the microstructure and mechanical properties are determined. The cast specimens are cut and polished by standard metallographic procedure. Optical micrographs are taken at different magnification to reveal the microstructure and B4C particulate distribution. The micro hardness and tensile test results indicate that there is a significant increase in these properties with the increase in B4C content.

scholarly journals Analysis of the Crystallization of AZ91 Alloy by Thermal and Derivative Analysis Method Intensively Cooled in Ceramic Shell

2014 ◽  
Vol 14 (1) ◽  
pp. 97-102 ◽  
Author(s):  
C. Rapiejko ◽  
B. Pisarek ◽  
E. Czekaj ◽  
T. Pacyniak
Keyword(s):  
Thermal Effect ◽  
Cooling Rate ◽  
Brinell Hardness ◽  
Optical Microscope ◽  
Az91 Alloy ◽  
Test Results ◽  
Micro Hardness ◽  
Derivative Analysis ◽  
Kinetics And Dynamics ◽  
Test Result

Abstract The work presents the test result of the influence of cooling rate on the microstructure of AZ91 alloy, Vickers micro-hardness and Brinell hardness. Studies cooling and crystallization of AZ91 alloy was cast into the ceramic shells preheated to 180 ° C and then air-cooled at ambient temperature or intensively super cooled in the liquid coolant. The TDA method was applied to record and characterize the thermal effect resulting from the phase transformations occurring during the crystallization of AZ91 alloy. The kinetics and dynamics of the thermal processes of crystallization of AZ91 alloy in the ceramic shells were determined. Metallographic tests were performed with the use of an optical microscope. A comparison of these test results with the thermal effect recorded by way of the TDA method was made. Influence of cooling rate of AZ91 on HV0, 01 micro-hardness and Brinell hardness alloy was examined

Microstructure and Hardness of Gray Cast Iron as a Product of Solidification in Permanent Mold

2020 ◽  
Vol 991 ◽  
pp. 37-43
Author(s):  
Agus Yulianto ◽  
Rudy Soenoko ◽  
Wahyono Suprapto ◽  
As’ad Sonief ◽  
Agung Setyo Darmawan ◽  
...  
Keyword(s):  
Cast Iron ◽  
Cooling Rate ◽  
Induction Furnace ◽  
Gray Cast Iron ◽  
Casting Process ◽  
Melting Process ◽  
Gray Cast ◽  
Outer Side ◽  
Permanent Mold ◽  
Test Results

Molds of metal are widely used in the casting process. The cooling rate in solidification of castings product with metal molds on the outer side and inner side is different. Therefore, sizes and types of phase will be also different. This study aims to investigate the microstructure andhardness of gray cast iron. To realize this research, the gray cast iron melting process was carried out in an induction furnace. Melted gray cast iron was poured into a Ferro Casting Ductile mold that has been through a preheating process at a temperature of 300 o C. The gray cast iron is then tested for composition, microstructure and hardness. The test results show that the part containing morecementite phase will be harder.

Effects of solution temperature and cooling rate on microstructure and micro-hardness of a hot compressed Ti-6Al-4V alloy

Vacuum ◽  
2019 ◽  
Vol 159 ◽  
pp. 191-199 ◽  
Author(s):  
Y.C. Lin ◽  
Yi Tang ◽  
Xiao-Yong Zhang ◽  
Chao Chen ◽  
Hui Yang ◽  
...  
Keyword(s):  
Cooling Rate ◽  
Solution Temperature ◽  
Micro Hardness

scholarly journals Finite Element Analysis of Temperature Distribution and Stress Behavior of Squeeze Pressure Composites

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
P. Gurusamy ◽  
T. Sathish ◽  
V. Mohanavel ◽  
Alagar Karthick ◽  
M. Ravichandran ◽  
...  
Keyword(s):  
Finite Element ◽  
Temperature Distribution ◽  
Cooling Rate ◽  
Base Alloy ◽  
Cast Alloy ◽  
Simulation Software ◽  
Engineering Industry ◽  
Effect Of Temperature ◽  
Cooling Curves ◽  
Squeeze Pressure

Aluminium-reinforced composites play a vital role in the engineering industry because of their better strength and stiffness. The properties are directly related to the solidification phenomenon of the cast alloy. The design engineer should understand the importance of the solidification behavior of base alloy and its reinforcement. Composites’ solidification study is rare, and the reviews are limited. The solidification process is analyzed using the finite element method (FEM), and this would fetch a lot of information about the cooling rate of the composites and also helps to reduce the time in experimentation. This paper reports and plots the cooling curves of Al/SiCp composites using simulation software. Cylindrical-shaped composites were developed using the squeeze casting method, and the experimental cooling curves were plotted using a K-type thermocouple. Composites samples were prepared at the following squeeze pressures: 0, 30, 50, 70, 100, and 130 MPa; melt and die temperature was kept constant at 800 and 400°C, respectively. The experimental and FEA cooling curves were compared, and it was agreed that the increase in the squeeze pressure increases the cooling rate of the developed composite. Furthermore, the effect of temperature distribution from the inner region of the melt and die material which causes the radial and tangential stress of components has also been examined.

scholarly journals Carbon Fibre - Copper Composites Obtained by Foil Casting

1994 ◽  
Vol 3 (2) ◽  
pp. 096369359400300
Author(s):  
W.K. Wtosiński ◽  
W. Olesińska ◽  
K. Pietrzak ◽  
D. Kaliński
Keyword(s):  
Thermal Expansion ◽  
Carbon Fibre ◽  
Casting Process ◽  
Fibre Content ◽  
Resistance Welding ◽  
Test Results ◽  
Micro Hardness ◽  
Electric Contacts

A method for production of carbon fibre - copper composites by foil casting is presented. As follows from the test results included, the foil casting process may be applied to produce the carbon fibre -copper composites. Thanks to the use continuous fibres, the method allows to obtain composites with fibres ordered directionally. Measurements of thermal expansion and micro-hardness of a composite with 30% fibre content, as well as examination of its microstructure are presented. The composites may, among others, find application in manufacturing of electrodes for resistance welding, electric contacts and expansion wafers for semiconductor power components.

scholarly journals A Statistical Evaluation of the Influence of Different Material and Process Parameters on the Heat Transfer Coefficient in Gravity Die Casting

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1367
Author(s):  
Nino Wolff ◽  
Golo Zimmermann ◽  
Uwe Vroomen ◽  
Andreas Bührig-Polaczek
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Die Casting ◽  
Local Heat Transfer ◽  
Mold Temperature ◽  
Local Heat ◽  
Mold Material ◽  
Transfer Coefficients ◽  
The Heat Transfer Coefficient

Local heat transfer in gravity die casting is of great importance for precision in terms of distortion, mechanical properties, and the quality of the castings due to its effect on solidification. Depending on contact conditions such as liquid melt to solid mold, a gap between mold and component, or contact pressure between casting and mold as a result of shrinkage, there are very large differences in heat transfer. The influences of mold material, mold coating and its influence of aging, mold temperature control, and layout on the heat transfer coefficient (HTC) were investigated experimentally for different contact cases. The experiments were carried out on a rotationally symmetrical experimental setup with modular exchangeable die inserts and cores using an AlSi7Mg0.3 alloy. From the results of the individual test series, the quantitative shares of the above-mentioned influencing variables in the respective effective heat transfer coefficients were determined by means of analysis of variance. From this, the parameters having the most significant influence on the local heat balance were derived.

Influence of Cooling Rate on the Microstructure in HCCI/Steel Bimetal Composite Hammer

2012 ◽  
Vol 538-541 ◽  
pp. 1041-1044 ◽  
Author(s):  
Ning Wei ◽  
Kai Wang ◽  
Xiang Kui Zhou ◽  
Qiang Wang ◽  
Qiang Liu ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Cooling Rate ◽  
Mold Material ◽  
Eutectic Carbides ◽  
Fast Cooling ◽  
Primary Carbides ◽  
Bimetal Composite

The HCCI/carbon steel bimetal composite hammer was prepared by bimetal liquid cast process and the effect of cooling rate, which is obtained by different mold material, on the microstructures of hypereutectic HCCI was studied. The results show that the primary carbides and eutectic carbides are refined with the increase of cooling rate. Good metallurgical combination of the HCCI/carbon steel bimetal hammer can be reached by bimetal liquid cast process with fast cooling mold.

A Novel Canning Technology for Forging of Gamma-TiAl Alloys

2007 ◽  
Vol 546-549 ◽  
pp. 1421-1426
Author(s):  
J. Zhang ◽  
Anja Kutzsche ◽  
K. Rosenberg ◽  
Christoph Leyens ◽  
Bernd Viehweger
Keyword(s):  
Stainless Steel ◽  
Cooling Rate ◽  
Glass Layer ◽  
Strain Rates ◽  
Coated Steel ◽  
Cooling Curves ◽  
Temperature Decrease ◽  
Tial Alloys ◽  
Stainless Steel Foil ◽  
Equiaxed Grains

A novel canning technology to forge gamma-TiAl alloys was developed at the BTU Cottbus. A TiAl specimen was encapsulated with multilayer stainless steel foil and glass. The steel foil layers prevented the heat loss through radiation and the glass layer reduced the temperature decrease through conduction. First, the effect of steel foil on the cooling rate was investigated. Cooling curves were recorded for TiAl specimens without steel foil layer, with 1, 2, 3 and 4 layers of steel foil, as well as with 3 coated steel foil layers, respectively. While the unprotected specimen cooled from 1200 °C to 1100 °C within 12 s, the specimen with 3 coated steel foil layers needed 52 s for the same temperature decrease. The efficiency of the glass layer was examined with forging of steel specimens. The cooling rate during forging of the specimen with a glass layer was only half of that without a glass layer. Based on the results, Ti-45Al-0.5Mo-0.5Cu-0.2Si specimens, canned with steel foil and glass, were successfully forged at strain rates of 0.1 s-1 and 0.04 s-1 with warm dies which were heated to 500 °C. Visual and metallographic examinations revealed no cracks, pores or micropores. The microstructures are fine-equiaxed grains.

Metastable Phenomena in the Thermally Activated Conductivity of Hydrogenated Amorphous Germanium (a-Ge:H)

1993 ◽  
Vol 297 ◽  
Author(s):  
T. DrÜsedau ◽  
D. Pang ◽  
E. Sauvain ◽  
P. Wickboldt ◽  
E.Z. Liu ◽  
...  
Keyword(s):  
Cooling Rate ◽  
Room Temperature ◽  
Equilibrium Temperature ◽  
Cooling Curves ◽  
Thermally Activated ◽  
Heating And Cooling ◽  
Higher Temperature ◽  
Hydrogenated Amorphous ◽  
Hydrogenated Amorphous Germanium ◽  
Good Agreement

The activated conductivity of a-Ge:H between room temperature and 460K was investigated using heating and cooling rates in the range between .001 and 0.1 K/s. A splitting of the cooling curves obtained at different rates, which defines the so called equilibrium temperature TE, is observed mainly between 420 and 430K. Taking into consideration that TE depends on the maximum cooling rate, the present results are in good agreement with those reported by Eberhardt et al. The higher cooling rate always leads to the lower conductivity at any temperature below TE. These effects can be rationalized in terms of a reversible shift of the Fermi level towards midgap at higher temperature. Though reversible changes of the mobility cannot be excluded, they cannot account for our set of experimental data. Rather, changes in the density of electronic states within the mobility gap can explain the effects observed.

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