scholarly journals Studies on Vacuum Induction Melting Process (1st Report)

DENKI-SEIKO ◽  
1958 ◽  
Vol 29 (1) ◽  
pp. 11-17,55
Author(s):  
A. Yamaki
Keyword(s):  
Melting Process ◽  
Vacuum Induction Melting ◽  
Induction Melting

Vacuum Induction Melting and Investment Casting Technologies Tailored to Near-Gamma TiAl Alloys

2007 ◽  
Vol 539-543 ◽  
pp. 1463-1468 ◽  
Author(s):  
Antonín Dlouhý ◽  
Kateřina Dočekalová ◽  
Ladislav Zemčík
Keyword(s):  
Investment Casting ◽  
Cost Effective ◽  
Melting Process ◽  
Vacuum Induction Melting ◽  
Crucible Wall ◽  
Induction Melting ◽  
Ceramic Shell ◽  
Shell Mould ◽  
Stress States ◽  
As Stress

The present study focuses on vacuum induction melting and investment casting of neargamma TiAl intermetallic alloys. The attention is mainly given to a cost-effective melting process in which a primary alloy ingot is re-melted in a ceramic crucible and cast into a ceramic shell mould. Two types of crucibles (based on Al2O3 and Y2O3) are considered. The most detrimental reactions that govern the contamination of the molten alloy with ceramic particles were determined. Results suggest that the crucible wall attack can be considerably limited by using either the Y2O3 (with no SiO2-type binder) or Al2O3 crucibles with a suitable coating. After pouring, a mechanical interaction associated with different thermal expansions of TiAl casts and ceramic shell moulds can result in serious product damage. A simple 1D-1D model of the cooling process was formulated and the heat flow as well as stress states in the cast-mould system were numerically solved. Process parameters (melt superheat, initial mould temperature, cooling kinetics and mould composition) were optimized in order to reduce the stress in the casts. The optimized parameters delimited a processing window in which complex-shaped TiAl castings like turbocharger wheels can be fabricated.

Study on Microstructure and Phase Composition of Co-8.8Al-9.8W Superalloy with Alloying Element Tantalum

2015 ◽  
Vol 1083 ◽  
pp. 37-39
Author(s):  
Yang Tao Xu ◽  
Qi Zhen Sha ◽  
Wan Li Zhao
Keyword(s):  
Phase Composition ◽  
Ball Mill ◽  
Melting Process ◽  
Xrd Analysis ◽  
Vacuum Induction Melting ◽  
Induction Melting ◽  
Pure Element ◽  
Alloying Element ◽  
Etching Solution ◽  
Electrolytic Etching

In order to study the effect of tantalum to the microstructure and phase composition of Co-8.8Al-9.8W-XTa (X=0,2,at%) superalloy. The Co-8.8Al-9.8W-XTa (X=0,2) supperalloy used pure element powder, according to the ratio of different atomic percentage composition to make ingredients. It is mixed by planetary ball mill, pressed into blocks after the melting shape. Vacuum induction melting process was prepared by melting, after grinding, polishing, and after a volume of 5% perchloric acid and 95% of the electrolytic etching solution prepared in ethanol corrosion observed after analysis of the microstructure and phase composition by OM and XRD analysis. It can be found that the 9.8W and 2Ta alloy were mainly composed of rich γ-Co matrix of austenite precipitation of γ phase and coherent with matrix of the L12 structure of γ′-Co3(Al,W) phase. In addition, Ta element has effect on grain refinement and the number of γ′-Co3(Al,W) phase refines grain.

Processing and Characterization of Superinvar for Space Application

2015 ◽  
Vol 830-831 ◽  
pp. 30-33 ◽  
Author(s):  
Rohit Kumar Gupta ◽  
Praveen Varma ◽  
V. Anil Kumar ◽  
P. Sarkar ◽  
Jaimin Desai ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Expansion ◽  
Thermomechanical Processing ◽  
Coefficient Of Thermal Expansion ◽  
Melting Process ◽  
Processing Parameters ◽  
Raw Material ◽  
Vacuum Induction Melting ◽  
Induction Melting ◽  
Process Selection

Material with ultra-low coefficient of thermal expansion (CTE) is required for mounting camera and other optical elements in satellite systems. Invar (64 Fe 36Ni) has been the work-horse material for this purpose. In recent years, modified version of conventional invar i.e. Superinvar with 5% cobalt (replacing 5% nickel) is being used to further bring down the errors in camera mountings due to thermal expansion. Processing of this alloy poses many challenges due to its requirement of ultra-low CTE. In the present work, melting and thermomechanical processing parameters were selected to meet the specified requirement of the alloy. The alloy was melted through vacuum induction melting process to obtain uniform and homogeneous chemistry and properties. Virgin raw material was used to achieve lowest carbon and manganese contents. Chemical composition thus obtained is found to be within the specification. Material was hot worked to refine the microstructure. Three different sizes of forged blocks were produced. Hot worked material was heat treated to obtain desirable and stable microstructure. Heat treatment cycle for stabilization was selected and used to retain carbon in the solution and minimize temporal growth. Mechanical properties (tensile strength and modulus of elasticity) and physical properties (CTE, thermal conductivity) were evaluated. Properties were found to be meeting the specification. It is observed that the material shows uniform single phase austenitic microstructure. The paper presents details of the process selection and challenges in processing of this alloy to obtain the targeted CTE < 0.6x10-6 per °C in the temperature range of 25°C to 150°C along with other desired mechanical properties.

Desulfurization Mechanism of K4169 Superalloy Using CaO Crucible in Vacuum Induction Melting Process

2018 ◽  
pp. 575-586
Author(s):  
Kewei Xie ◽  
Bo Chen ◽  
Mengshu Zhang ◽  
Zhanhui Du ◽  
Xiangdong Zha ◽  
...  
Keyword(s):  
Melting Process ◽  
Vacuum Induction Melting ◽  
Induction Melting

Extraction of Rare Earth Elements from Permanent Magnet Scraps by VIM-HMS Method

2016 ◽  
Vol 863 ◽  
pp. 139-143
Author(s):  
Yu Yang Bian ◽  
Shu Qiang Guo ◽  
Kai Tang ◽  
Wei Zhong Ding
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Magnetic Separation ◽  
Permanent Magnets ◽  
Graphite Crucible ◽  
Melting Process ◽  
Deionized Water ◽  
Vacuum Induction Melting ◽  
Induction Melting ◽  
The Rare Earth

VIM-HMS method is a novel process to extract REEs (rare earth elements) from NdFeB based permanent magnets. The NdFeB materials were melted in graphite crucible by VIM (vacuum induction melting) process, and the carbon saturated NdFeBCsat alloy was obtained. The NdFeBCsat alloy was mechanically pulverized and hydrolyzed in deionized water. In the HMS (Hydrolysis and magnetic separation) process, the neodymium carbide phase in the alloy reacted with water easily, and the rare earth hydroxides and the iron residues were separated by magnetic separation. The purity of the rare earth hydroxides was more than 99%, and the extraction ratio of the REEs is about 93%.

Microstructure in soft magnetic E3 (S1, Al) (Sendust) alloys

1988 ◽  
Vol 46 ◽  
pp. 770-771
Author(s):  
June D. Kim
Keyword(s):  
Electron Microscopy ◽  
Magnetic Properties ◽  
Ternary Phase Diagram ◽  
Vertical Tube ◽  
Vacuum Induction Melting ◽  
Induction Melting ◽  
Soft Magnetic ◽  
Quenching Temperature ◽  
Thin Foils ◽  
Vertical Tube Furnace

Iron-base alloys containing 8-11 wt.% Si, 4-8 wt.% Al, known as “Sendust” alloys, show excellent soft magnetic properties. These magnetic properties are strongly dependent on heat treatment conditions, especially on the quenching temperature following annealing. But little has been known about the microstructure and the Fe-Si-Al ternary phase diagram has not been established. In the present investigation, transmission electron microscopy (TEM) has been used to study the microstructure in a Sendust alloy as a function of temperature.An Fe-9.34 wt.% Si-5.34 wt.% Al (approximately Fe3Si0.6Al0.4) alloy was prepared by vacuum induction melting, and homogenized at 1,200°C for 5 hrs. Specimens were heat-treated in a vertical tube furnace in air, and the temperature was controlled to an accuracy of ±2°C. Thin foils for TEM observation were prepared by jet polishing using a mixture of perchloric acid 15% and acetic acid 85% at 10V and ∼13°C. Electron microscopy was performed using a Philips EM 301 microscope.

UDIMET 700

Alloy Digest ◽  
1987 ◽  
Vol 36 (1) ◽  
Keyword(s):  
Gas Turbines ◽  
Base Alloy ◽  
Heat Treating ◽  
Vacuum Arc ◽  
Vacuum Induction Melting ◽  
Induction Melting ◽  
Nickel Base Alloy ◽  
Vacuum Arc Remelting ◽  
Temperature Performance ◽  
Nickel Base

Abstract UDIMET 700 is a wrought nickel-base alloy produced by vacuum-induction melting and further refined by vacuum-arc remelting. It has excellent mechanical properties at high temperatures. Among its applications are blades for aircraft, marine and land-based gas turbines and rotor discs. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ni-51. Producer or source: Special Metals Corporation. Originally published March 1959, revised January 1987.

ALLVAC AC718

Alloy Digest ◽  
1991 ◽  
Vol 40 (7) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Tensile Properties ◽  
Heat Treating ◽  
Vacuum Arc ◽  
Vacuum Induction Melting ◽  
Induction Melting ◽  
Good Ductility

Abstract Allvac 718 is produced by vacuum induction melting followed by vacuum arc or electroslag consumable remelting. Th alloy has excellent strength and good ductility up to 1300 F (704 C). It also has excellent cryogenic properties. It has unique welding characteristics. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ni-394. Producer or source: Allvac Inc..

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