scholarly journals Cooling Rate, Hardness and Microstructure of Aluminum Cast Alloys

2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Hasan Akhyar
Keyword(s):  
Cooling Rate ◽  
Solidification Rate ◽  
Pure Aluminum ◽  
High Hardness ◽  
Casting Process ◽  
Mold Temperature ◽  
Cooling Curve ◽  
Pouring Temperature ◽  
Aluminum Cast Alloys ◽  
Cast Alloys

This experiment investigated the cooling curve behavior, hardness and microstructure of two aluminum alloys produced by casting process. There are Al-1.37Zn-1.19Si and Al-1.66Si-1.35Zn derived from melting and alloying a pure aluminum with ADC12 (Al-Si) ingot. Cooling curve recorded from both those two alloys with pouring temperature at 710 oC and the mold temperature kept constant at 220 oC. The result shows, a freezing range of Al-1.37Zn-1.19Si alloy is 643–348 oC and Al-1.66Si-1.35Zn alloy is 621–401 oC. Then cooling rate obtained for Al-1.37Zn-1.19Si is 55.56 oC/S, and Al-1.66Si-1.35Zn is 30.09 oC/S. TThe higher hardness is 40.42 BHN at Al 1.66 Si-1.35Zn, while the lower value is 34.62 BHN on Al-1,37Zn-1,19Si alloy. The hardness value found higher when cooling rate is shorted. The number of silicon present on microstructure is highest in Al-1.37Zn-1.19Si alloy but the hardness value decreases. This is caused by the distribution of the silicon content in the alloy is irregular. It was found that the solidification rate had an effect on hardness, where the freezing rate obtained a high hardness value.

scholarly journals Cooling Rate, Hardness and Microstructure of Aluminum Cast Alloys

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Hasan Akhyar
Keyword(s):  
Cooling Rate ◽  
Solidification Rate ◽  
Pure Aluminum ◽  
High Hardness ◽  
Casting Process ◽  
Mold Temperature ◽  
Cooling Curve ◽  
Pouring Temperature ◽  
Aluminum Cast Alloys ◽  
Cast Alloys

This experiment investigated the cooling curve behavior, hardness and microstructure of two aluminum alloys produced by casting process. There are Al-1.37Zn-1.19Si and Al-1.66Si-1.35Zn derived from melting and alloying a pure aluminum with ADC12 (Al-Si) ingot. Cooling curve recorded from both those two alloys with pouring temperature at 710 oC and the mold temperature kept constant at 220 oC. The result shows, a freezing range of Al-1.37Zn-1.19Si alloy is 643–348 oC and Al-1.66Si-1.35Zn alloy is 621–401 oC. Then cooling rate obtained for Al-1.37Zn-1.19Si is 55.56 oC/S, and Al-1.66Si-1.35Zn is 30.09 oC/S. TThe higher hardness is 40.42 BHN at Al 1.66 Si-1.35Zn, while the lower value is 34.62 BHN on Al-1,37Zn-1,19Si alloy. The hardness value found higher when cooling rate is shorted. The number of silicon present on microstructure is highest in Al-1.37Zn-1.19Si alloy but the hardness value decreases. This is caused by the distribution of the silicon content in the alloy is irregular. It was found that the solidification rate had an effect on hardness, where the freezing rate obtained a high hardness value.

Numerical Simulation of Casting Deformation and Stress of A356 Aluminum Alloy Thin-Walled Frame Casting

2021 ◽  
Vol 1033 ◽  
pp. 24-30
Author(s):  
Yi Dan Zeng ◽  
Li Tong He ◽  
Jin Zhang
Keyword(s):  
Aluminum Alloy ◽  
Casting Process ◽  
Mold Temperature ◽  
Hot Cracking ◽  
Thin Wall ◽  
A356 Aluminum Alloy ◽  
Pouring Temperature ◽  
Thin Walled ◽  
Alloy Castings ◽  
A356 Aluminum

One of the main reasons for the scrap of cast thin-wall frame aluminum alloy castings is deformation and cracking. It is an effective method for solving the problem by predicting the distribution of casting stress, clarifying the size of the deformation and the location of the crack, and taking necessary measures in the process. This paper uses the ProCAST software to simulate the thermal stress coupling of A356 thin-walled frame castings, analyzes the influence of pouring temperature, pouring speed and mold temperature on the stress field distribution of castings, predicts the hot cracking trend and deformation, and optimizes Casting process..

The Study of Dendrite Arm Spacing (DAS) on Acoustical of Tin Bronze 20Sn Alloy as Gamelan Bali Materials

2017 ◽  
Vol 889 ◽  
pp. 133-137
Author(s):  
I. Ketut Gede Sugita ◽  
I. Gusti Ngurah Priambadi
Keyword(s):  
Solidification Rate ◽  
Casting Process ◽  
Mold Temperature ◽  
Casting Temperature ◽  
Important Process ◽  
Acoustical Characteristic ◽  
Dendrite Arm Spacing ◽  
Tin Bronze ◽  
Crucible Furnace ◽  
The Difference

Bronze especially tin bronze is mostly used as material of traditional music instrument such as gamelan, cymbals, or bells. Casting process becomes an important process in making gamelan. Solidification is the most important process in the casting. This study is designed to evaluate variant of solidification rate on casting process of conventional bronze (tin bronze) as gamelan material. This study aimed at finding variant of Dendrite Arm Spacing (DAS) on acoustical characteristic of bronze alloy. The alloy of Cu–20Sn is chosen as the composition of tin-bronze because this composition is widely used as the gamelan material. Variant of solidification rate is designed by varying mold temperature and casting temperature. The bronze is melted in crucible furnace until 1050, 1100, 1100oC. Then, the melted material was poured into the mold in 400°C temperature. This study showed that increase of casting temperature influence the decrease of solidification rate which affecting the longer time of solidification. The difference of solidification rate affected on the construction of micro structure and the dendrite (DAS) formed. The size of the dendrite forms affected the mechanical and acustical tin bronze.

scholarly journals The Effect of Solidification Rate on the Microstructure and Mechanical Properties of Pure Magnesium

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1264
Author(s):  
Murtatha M. Jamel ◽  
Hugo Lopez ◽  
Benjamin Schultz ◽  
Wilkistar Otieno
Keyword(s):  
Mechanical Properties ◽  
Cooling Rate ◽  
Fracture Behavior ◽  
Solidification Rate ◽  
Casting Process ◽  
Grain Structure ◽  
Rockwell Hardness ◽  
Cooling Rates ◽  
Liquid Co2 ◽  
Processing Defects

Magnesium, Mg, has been widely investigated due to its promising potential as magnesium alloys for various applications, particularly as biomedical implantation devices among other medical applications. This work investigates the influence of different cooling rates on the strength of pure Mg. The cooling rates were set to cover a low cooling rate LCR (0.035 °C/s) in an insulated furnace, a moderate cooling rate MCR (0.074 °C/s) in uninsulated-ends furnace, and a high cooling rate HCR (13.5 °C/s) in liquid CO2. The casting process was accomplished using a closed system of melting and cooling due to the reactivity-flammability of magnesium in order to minimize processing defects and increase the safety factor. The as-cast samples were metallographically examined for their microstructure, and properties such as impact strength, hardness, and tension were determined. Increasing the solidification rate from 0.035 °C/s to 0.074 °C/s increased the hardness from 30 to 34 Rockwell Hardness and the UTS from 48 to 67 MPa. A higher solidification rate of 13.5 °C/s further enhanced the hardness to 48 Rockwell Hardness and the UTS to 87 MPa in comparison to the 0.074 °C/s cooling rate. Additionally, the fracture behavior and morphology were investigated. It was found that in general, the mechanical properties tended to improve by refining the grain structure.

Voids in Quenched Nickel

1968 ◽  
Vol 26 ◽  
pp. 266-267
Author(s):  
J. J. Laidler
Keyword(s):  
Electron Beam ◽  
Ambient Temperature ◽  
Cooling Rate ◽  
Three Dimensional ◽  
Cooling Curve ◽  
Polycrystalline Nickel ◽  
Quenching Temperature ◽  
Long Tail ◽  
Diffusion Pump

The presence of three-dimensional voids in quenched metals has long been suspected, and voids have indeed been observed directly in a number of metals. These include aluminum, platinum, and copper, silver and gold. Attempts at the production of observable quenched-in defects in nickel have been generally unsuccessful, so the present work was initiated in order to establish the conditions under which such defects may be formed.Electron beam zone-melted polycrystalline nickel foils, 99.997% pure, were quenched from 1420°C in an evacuated chamber into a bath containing a silicone diffusion pump fluid . The pressure in the chamber at the quenching temperature was less than 10-5 Torr . With an oil quench such as this, the cooling rate is approximately 5,000°C/second above 400°C; below 400°C, the cooling curve has a long tail. Therefore, the quenched specimens are aged in place for several seconds at a temperature which continuously approaches the ambient temperature of the system.

Tribological characteristics of AA8090-WC-ZrC metal matrix composites prepared by stir casting process for Aerospace applications

2021 ◽  
Vol 73 (6) ◽  
pp. 980-985
Author(s):  
Kalaiyarasan A ◽  
Sundaram S ◽  
Gunasekaran K ◽  
Bensam Raj J.
Keyword(s):  
Metal Matrix ◽  
Materials Science ◽  
Scientific Information ◽  
High Hardness ◽  
Hardness Test ◽  
Casting Process ◽  
Stir Casting ◽  
Hybrid Particles ◽  
Content Type ◽  
The Impact

Purpose Aerospace field is demanding a material with superior strength and high resistance against wear, tear and corrosion. The current study aimed to develop a new material with high performance to be applicable in aerospace field Design/methodology/approach A metal matrix composite AA8090-WC-ZrC was fabricated using stir casting method and its tribological behavior was investigated. Totally, five composites viz. AA/Z, AA/W, AA/WZ (1:3), AA/WZ (1:1) & AA/WZ (3:1) were prepared. Micro hardness, tensile and wear study were performed on the fabricated composites and the results were compared with AA8090 alloy Findings Vickers hardness test resulted that the AA/W composite showed the higher hardness value of 160 HB compared to other materials due to the reinforcing effect of WC particles with high hardness. Tensile test reported that the AA/W composite displayed the maximum tensile strength of 502 MPa owing to the creation of more dislocation density. Further, wear study showed that the AA/W composite exhibited the least wear rate of 0.0011 mm3/m because of the more resisting force offered by the WC particles. Furthermore, the AA/W composite showed the slightest mass loss of 0.0028 g and lower COF value of 0.31 due to the hinder effect of WC particle to the movement of atoms in AA8090 alloy Originality/value This work is original in the field of aerospace engineering and materials science which deals with the fabrication of AA8090 alloy with the reinforcement particles such as tungsten carbide and zirconium carbide. The impact of the combination of hybrid particles and their volume fractions on the tribological properties has been investigated in this work. This work would provide new scientific information to society.

On the Construction of Analytical Cooling Curves from ASTM D6200 Data Using Multi-Variable Gradient Descent Method

2021 ◽  
Author(s):  
James Jan ◽  
D. Scott MacKenzie
Keyword(s):  
Cooling Rate ◽  
Oil Quality ◽  
Standard Test ◽  
Descent Method ◽  
Test Method ◽  
Cooling Curve ◽  
Gradient Descent Method ◽  
Mathematical Function ◽  
Current Standard ◽  
Characteristic Points

Abstract ASTM D6200 is a standard test method to evaluate cooling characteristics of quench oils. The test produces six discrete numbers representing the cooling characteristics: three temporal scales (time to cool to 600°C, 400°C, and 200°C), two cooling rates (max cooling rate and cooling rate at 300°C), and one temperature scale (at max cooling rate). One of the main purposes of ASTM D6200 is to monitor the oil quality to ensure gears are properly quenched. The current standard only includes specifications for gear quenching oil and its applications are limited to physical testing. The intent of this research is to explore the possibility of broadening the support for more quenchants and extending applications to virtual engineering. This research includes two parts. The first part is the development of a systematic method to identify the characteristic points of a cooling curve. The second part is the construction of an analytical cooling curve based on the characteristic points. The analytical cooling curve is a mathematical function of temperature versus time that can provide temperature at any given time in the quenching process. In addition, the curve is differentiable to provide the cooling rate information at any given time as well.

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.

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