Effect of Ultrasonic Melt Treatment on Solidification Structure of Fe-36Ni Invar Alloy

AbstractThe effect of ultrasonic treatment on the solidification structure of Fe-36Ni invar alloy was investigated. The experiment results showed that the ultrasonic treatment before its solidification had no significant effect on the solidification structure. However, when ultrasonic was inputted into the molten alloy during its solidification process, the primary dendrites were broken up into lots of fragments and solidification structure was refined significantly. When ultrasonic treatment was applied in the melt doped with yttrium before its solidification, ultrasonic cavitation could break up precipitates into many small ones, which could refine its solidification structure as nucleation cores. In samples containing yttrium treated by ultrasonic at 1753 K, the number of the precipitates was 623/mm2 and its average size was 2.18 µm; while at 1803 K, they were 604/mm2 and 2.34 µm respectively. The ultrasonic cavitation had a similar effect at two different temperatures. The solidification structure refined greatly at 1753 K was due to its low pouring temperature.

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A Study on the Effect of Ultrasonic Treatment on the Microstructure of Sn-30 wt.% Bi Alloy

Materials ◽

10.3390/ma11101870 ◽

2018 ◽

Vol 11 (10) ◽

pp. 1870

Author(s):

Shuo Wang ◽

Jinwu Kang ◽

Xiaopeng Zhang ◽

Zhipeng Guo

Keyword(s):

Ultrasonic Treatment ◽

Acoustic Streaming ◽

Eutectic Structure ◽

Eutectic Phase ◽

Ultrasonic Cavitation ◽

Mixed Effect ◽

Temperature Range ◽

Different Temperatures

The effect of ultrasonic treatment on the microstructure of Sn-30 wt.% Bi alloy was studied at different temperatures. Results showed that the ultrasonic treatment could effectively refine the microstructure of Sn-30 wt.% Bi alloy at a temperature range between the liquidus and solidus. Application of the ultrasound could fragment the primary Sn dendrites during solidification due to a mixed effect of ultrasonic cavitation and acoustic streaming. The divorced eutectic formed when the ultrasonic treatment was applied for the whole duration of the solidification. The eutectic phase grew and surrounded the primary Sn dendrite, and pure Bi phase grew in between the Sn dendritic fragments. The mechanism of the fragmentation of dendrites and the divorced eutectic structure by ultrasonic treatment was discussed.

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Thixocasting of Al-7%Si Alloy Billets Prepared by Ultrasonic Treatment

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.256.276 ◽

2016 ◽

Vol 256 ◽

pp. 276-281

Author(s):

Waleed Khalifa ◽

Yoshiki Tsunekawa

Keyword(s):

Ultrasonic Treatment ◽

Melt Treatment ◽

Intermetallic Particles ◽

Eutectic Si ◽

Feedstock Production ◽

Dendritic Microstructures ◽

Ultrasonic Melt Treatment ◽

Highly Uniform

The feasibility of using the ultrasonic melt treatment to prepare billets for thixocasting process of hypoeutectic Al-7%Si alloys was studied in this paper. The work covered the billet preparation, soaking treatments and thixocasting process, with focus on the microstructural features in each case. The results showed that the use of ultrasonic treatment in billet preparation resulted in highly uniform, fine and non-dendritic microstructures. Billets with globule sizes as small as 58 µm, and roundness of more than 0.7 were obtained by ultrasonic melt treatment. Different soaking conditions before thixocasting were done and the optimum from which was the soaking for 5 min at 580°C, which resulted in thixocast parts with excellent combination of fine globules of 80 µm and roundness of 0.7 - 0.81. The eutectic Si, as well, was greatly refined by the ultrasonic thixocasting process. Furthermore, high-Fe ultrasonic treated billets, which were thixocasted successfully, exhibited Fe-intermetallic particles in highly desirable fine compacted form. These results reveal the feasibility and competence of UST as a potential route for feedstock production.

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Effect of ultrasonic melt treatment on the microstructure and tensile properties of Al-25% Si alloy assisted by phosphorus addition

International Journal of Materials Research (formerly Zeitschrift fuer Metallkunde) ◽

10.1515/ijmr-2020-7919 ◽

2021 ◽

Vol 112 (4) ◽

pp. 288-294

Author(s):

Bo Dang ◽

Zengyun Jian ◽

Junfeng Xu

Keyword(s):

Tensile Strength ◽

Tensile Properties ◽

Unit Area ◽

Phosphorus Addition ◽

Minimum Value ◽

Primary Si ◽

Melt Treatment ◽

Ultrasonic Intensity ◽

Ultrasonic Melt Treatment ◽

Average Size

Abstract The effects of ultrasonic melt treatment (UST) on the microstructure and tensile properties of Al-25% Si alloys with and without phosphorus addition were investigated. The average size of the primary Si firstly decreased and then increased with the rise of the ultrasonic intensity. The minimum value is about 25.4 and 32.8 μm when the ultrasonic intensity is 900 W with phosphorus addition and 1 200 W without phosphorus addition. The average number of primary Si per unit area firstly increased and then decreased in both alloys with increasing of ultrasonic intensity. Both tensile strength and elongation were improved mainly due to the refinement of microstructure by UST. Finally, the mechanism of UST on the primary Si is discussed.

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Ultrasonic Treatment of Magnesium Alloy Melts and its Effects on Solidification Microstructures

Materials Science Forum ◽

10.4028/www.scientific.net/msf.546-549.129 ◽

2007 ◽

Vol 546-549 ◽

pp. 129-132 ◽

Cited By ~ 15

Author(s):

Zi Qiang Zhang ◽

Qi Chi Le ◽

Jian Zhong Cui

Keyword(s):

Magnesium Alloy ◽

Magnesium Alloys ◽

Ultrasonic Treatment ◽

High Intensity ◽

Processing Time ◽

Ultrasonic Processing ◽

Ultrasonic Power ◽

Melt Treatment ◽

Ultrasonic Melt Treatment ◽

Solidification Microstructures

The effects of high intensity ultrasonic melt treatment on the microstructure of magnesium alloys were investigated in this paper. Magnesium melts were treated with power ultrasonic wave and then cooled to a predetermined temperature. With the increase in ultrasonic power, the structure exhibited refined and spheroidzed crystal grains. After further increasing the ultrasonic power, the grains tended to somewhat coarsened. And increasing the ultrasonic processing time led to a grain refinement of magnesium alloy.

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Ultrasonic Rheo-Diecasting of A383 Aluminum Alloy

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.256.282 ◽

2016 ◽

Vol 256 ◽

pp. 282-287 ◽

Cited By ~ 2

Author(s):

Waleed Khalifa ◽

Yoshiki Tsunekawa ◽

Shimaa El-Hadad

Keyword(s):

Aluminum Alloy ◽

Treatment Temperature ◽

Shot Sleeve ◽

Semisolid State ◽

Melt Treatment ◽

Intermetallic Particles ◽

Eutectic Si ◽

Different Temperatures ◽

Ultrasonic Melt Treatment ◽

Fe Intermetallics

In this study, un-refined A383 aluminum alloy was cast at different temperatures using ultrasonic melt treatment. The liquid alloy was treated by ultrasonic vibrations in the crucible and/or in the shot sleeve of a pressure diecasting machine. The treatment temperature extended to the semisolid temperature range. The UST melt could be injected into the die cavity while being in the semisolid state which is known as rheodiecasting. The results showed that ultrasonic treatment resulted in finer microstructure, globular Fe-intermetallic particles and partially modified eutectic Si. For samples solidified in shot sleeve: Fe-intermetallics become compacted with UST at all positions of ingot. Si particles are compacted in less acicular form near to horn and acicular at other positions. For the rheo-diecasting experiments, with UST treatment in the crucible and die casting, at 600-588 C and 588-578C, Fe-intermetallics were observed in compact form, and Si particles were highly modified.

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Effect of Ultrasonic Treatment on Microstructures of Mg-Ca Binary Alloy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.139-141.677 ◽

2010 ◽

Vol 139-141 ◽

pp. 677-680

Author(s):

Zhi Qiang Zhang ◽

Qi Chi Le ◽

Jian Zhong Cui

Keyword(s):

Magnesium Alloy ◽

Grain Refinement ◽

Magnesium Alloys ◽

Ultrasonic Treatment ◽

High Intensity ◽

Processing Time ◽

Ultrasonic Processing ◽

Ultrasonic Power ◽

Melt Treatment ◽

Ultrasonic Melt Treatment

The effects of high intensity ultrasonic melt treatment on the microstructure of magnesium alloys were investigated in this paper. Magnesium melts were treated with power ultrasonic wave and then cooled to a predetermined temperature. With the increase in ultrasonic power, the structure exhibited refined and spheroidzed crystal grains. After further increasing the ultrasonic power, the grains tended to somewhat coarsened. Increasing the ultrasonic processing time led to a grain refinement of magnesium alloy.

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Effect of Pouring Temperature and Melt Treatment on Microstructure of Lost Foam Casting of AL-Si LM6 Alloy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.264-265.295 ◽

2011 ◽

Vol 264-265 ◽

pp. 295-300 ◽

Cited By ~ 13

Author(s):

Majid Karimian ◽

Ali Ourdjini ◽

Mohd Hasbullah Idris ◽

M. Bsher ◽

A. Asmael

Keyword(s):

Cast Alloy ◽

Eutectic Silicon ◽

Lost Foam Casting ◽

Grain Refiner ◽

Pouring Temperature ◽

Casting Quality ◽

Melt Treatment ◽

Different Temperatures ◽

Lost Foam ◽

Porosity Percentage

This paper presents the experimental investigation conducted on Al-Si cast alloy (LM6) cast using lost foam process. The main objective of the research is to investigate the effect of pouring temperature, section thickness and melt treatment on the microstructure of the lost foam casting of Al-Si alloy. Step pattern with five different sections was prepared from 20 kg/m³ density foam and poured at five different temperatures; 700, 720, 740, 760, and 780 with and without the addition of AlTiB as grain refiner. Analysis on microstructure, eutectic silicon spacing and porosity percentage were conducted to determine the effect of both parameters. The results show that pouring temperature has significant influence on the quality as well as microstructure of the lost foam casting of LM6 Al-Si alloy. Lower pouring temperature was found to produce finer microstructure casting. However, the addition of AlTiB as grain refiner did not affect the produced castings significantly whether in terms casting quality or microstructure.

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About Ultrasonic Melt Treatment during Solidification and its Influence on Grain Size and Mechanical Properties of Magnesium Alloy AZ 91

Materials Science Forum ◽

10.4028/www.scientific.net/msf.649.295 ◽

2010 ◽

Vol 649 ◽

pp. 295-300 ◽

Cited By ~ 1

Author(s):

Katja Pranke ◽

Klaus Eigenfeld

Keyword(s):

Mechanical Properties ◽

Grain Size ◽

Magnesium Alloy ◽

Maximum Amplitude ◽

Solidification Process ◽

Cooling Curves ◽

Constant Frequency ◽

Melt Treatment ◽

Ultrasound Generator ◽

Ultrasonic Melt Treatment

We investigated the influence of varying amplitudes at constant frequency on the grain size and mechanical properties of magnesium alloy AZ 91. Our experimental setup consists of an ultrasound generator connected to a steel gravity die by screw fitting. Magnesium alloy AZ 91 has been melted in a closed-argon-flooded steel crucible and poured into the die while ultrasound was generated. Cooling curves were recorded during the whole solidification process. The grain size and the mechanical properties were determined and analyzed. As a result, we achieved reduction in grain size as well as an increase in tensile strengths for amplitudes of up to 40% of the maximum amplitude. Yield strengths could be minimally improved in all experiments. The values of elongation and hardness (Brinell) could also be improved for nearly all investigated amplitudes. In summary it is possible to achieve both: grain refinement and increase in tensile strength, hardness and elongation.

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