scholarly journals Powder Metallurgy Synthesis of Heusler Alloys: Effects of Process Parameters

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1596 ◽  
Author(s):  
Riaz Ahamed ◽  
Reza Ghomashchi ◽  
Zonghan Xie ◽  
Lei Chen

Ni45Co5Mn40Sn10 Heusler alloy was fabricated with elemental powders, using a powder processing route of press and sinter, in place of vacuum induction melting or arc melting route. The effects of process parameters, such as compaction load, sintering time, and temperature, on the transformation characteristics and microstructures of the alloy were investigated. While the effect of compaction pressure was not significant, those of sintering time and temperature are important in causing or annulling martensitic transformation, which is characteristic of Heusler alloys. The processing condition of 1050 °C/24 h was identified to be favorable in producing ferromagnetic Heusler alloy. Longer durations of sintering resulted in an increased γ-phase fraction, which acts as an impediment to the structural transformation.

Author(s):  
Vairamuthu J ◽  
Senthil Kumar A ◽  
Stalin B ◽  
Ravichandran M

In this paper, the aluminium based metal matrix composite material has been developed via powder metallurgy (PM) route by considering the various input process parameters. Sintering time, sintering temperature and compaction pressure are the three main factors used as input process parameters which are varied at three levels. Investigations have been planned with reference to the experimental design of L9 orthogonal array using a 3x3 matrix. The density, Vickers hardness and compression strength are experimented and analyzed. The influence of individual input parameters has been analyzed using Taguchi based S/N ratio and analysis of variance (ANOVA). The optimum parameter levels to achieve less density, high hardness and high compressive strength were identified through the main effect plots. Experimental results indicate that the sintering temperature and compaction pressure highly influences properties such as density and hardness. Similarly, compression strength mainly depends on sintering time and sintering temperature. Through ANOVA analysis, it was also confirmed that the selected parameter levels of the optimum sintering time at an average compaction pressure and sintering temperature will produce the best metal matrix composite material.


Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 292 ◽  
Author(s):  
Kun Sun ◽  
Weixiang Peng ◽  
Longlong Yang ◽  
Liang Fang

Selective laser melting (SLM) to fabricate Al0.5CoCrFeNi high entropy alloys with pre-mixed powders was studied in this paper. The influences of process parameters including laser power, scanning speed, and hatch spacing on the relative density of high-entropy alloys (HEAs) were investigated. A relative density of 99.92% can be achieved by optimizing the SLM process parameters with laser power 320 W, scanning speed 800 mm/s, and hatch spacing of 60 μm, respectively. Moreover, the microstructure of the HEAs was also studied using scanning electron microscopy (SEM) and x-ray diffraction (XRD). It was found that the microstructure of the HEAs was only composed of face-centered cubic and body-centered cubic phases, without complex intermetallic compounds. The mechanical properties of the HEAs were also characterized. At ambient temperature, the alloys had a high yield strength of about 609 MPa, tensile strength about 878 MPa, and hardness about 270 HV. Through a comparison with the corresponding alloys fabricated by vacuum induction melting, it can be concluded that the high entropy alloys fabricated by SLM had fine microstructures and improved mechanical properties.


Micromachines ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 218 ◽  
Author(s):  
Emanuele Cannella ◽  
Chris Valentin Nielsen ◽  
Niels Bay

Electro sinter forging (ESF) represents an innovative manufacturing process dealing with high electrical currents. Classified in the category of electrical current assisted sintering (ECAS) processes, the main principle is that Joule heating is generated inside the compacted powder, while the electrical current is flowing. The process is optimized through the analysis of the main process parameters, namely the electrical current density, sintering time, and compaction pressure, which are also evaluated as process fingerprints. The analysis was conducted on commercially pure titanium powder. Small discs and rings were manufactured for testing. The influence of the process parameters was analysed in terms of the final material properties. The relative density, microstructures, hardness, and tensile and compressive strengths were analysed concerning their validity as product fingerprints. Microstructural analyses revealed whether the samples were sintered or if melting had occurred. Mechanical properties were correlated to the process parameters depending on the material. The different sample shapes showed similar trends in terms of the density and microstructures as a function of the process parameters.


Author(s):  
June D. Kim

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.


Alloy Digest ◽  
1987 ◽  
Vol 36 (1) ◽  

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.


Alloy Digest ◽  
1991 ◽  
Vol 40 (7) ◽  

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..


Alloy Digest ◽  
1990 ◽  
Vol 39 (12) ◽  

Abstract NICKEL VAC N was originally developed as a container material for molten fluoride salts. It is a moderate strength, solid solution strengthened alloy with good oxidation resistance to 1800 F. It has excellent resistance to fluoride salts in the range 1300-1600 F. It is produced by vacuum induction melting followed electroslag remelting. 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, and joining. Filing Code: Ni-388. Producer or source: Teledyne Allvac.


Alloy Digest ◽  
1990 ◽  
Vol 39 (11) ◽  

Abstract NICKEL VAC X-751 is a modification of NICKEL VAC X-750 carrying higher aluminum content (0.90-1.50 vs 0.4-1.0%). This raises the maximum service temperature 100 F(55 C) to 1600 F(871 C). NICKEL VAC X-751 has a simplified and shortened heat treating cycle relative to NICKEL VAC X-750. It is produced by vacuum induction melting followed by vacuum arc or electroslag remelting. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ni-387. Producer or source: Teledyne Allvac.


Alloy Digest ◽  
1972 ◽  
Vol 21 (6) ◽  

Abstract UDIMET 90 is a nickel-base alloy developed for elevated-temperature service. It is produced by vacuum induction melting and vacuum arc remelting techniques to develop optimum properties. 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-174. Producer or source: Special Metals Corporation.


Alloy Digest ◽  
1990 ◽  
Vol 39 (12) ◽  

Abstract VASCOMAX T-300 is an 18% nickel maraging steel in which titanium is the primary strengthening agent. It develops a tensile strength of about 300,000 psi with simple heat treatment. The alloy is produced by Vacuum Induction Melting/Vacuum Arc Remelting. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: SA-454. Producer or source: Teledyne Vasco.


Sign in / Sign up

Export Citation Format

Share Document