scholarly journals Pressure-Assisted Development and Characterization of Al-Fe Interface for Bimetallic Composite Castings: An Experimental and Statistical Investigation for a Low-Pressure Regime

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1687
Author(s):  
Tayyiba Rashid ◽  
Muhammad Qaiser Qaiser Saleem ◽  
Nadeem Ahmad Ahmad Mufti ◽  
Noman Asif ◽  
M. Kashif Ishfaq ◽  
...  
Keyword(s):  
Optimization Technique ◽  
Applied Pressure ◽  
Low Pressure ◽  
Interface Layer ◽  
Statistical Investigation ◽  
Holding Time ◽  
Pouring Temperature ◽  
Aluminum Composite ◽  
Bimetallic Composite ◽  
Pressure Regime

A review of the available literature indicates that the development of metal-reinforced castings present intriguing prospects but carry inherent challenges owing to differences in thermal coefficients, chemical affinities, diffusion issues and the varying nature of intermetallic compounds. It is supported that pressure application during solidification may favorably influence the dynamics of the aforementioned issues; nevertheless, not only certain limitations have been cited, but also some pressure and process regimes have not yet been investigated and optimized. This work employs the pressure-assisted approach for bimetallic steel-reinforced aluminum composite castings at a low-pressure regime and thoroughly investigates the role of three process parameters, namely pouring temperature (800–900 °C), pressure (10–20 bars) and holding time (10–20 s), for producing sound interfaces. The Taguchi L9 orthogonal array has been employed as the Design of the Experiment, while dominant factors have been determined via analysis of variance and the grey relational analysis multi-objective optimization technique. Supplementary analysis through optical micrographs, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) has been utilized to quantify interfacial layer thicknesses and to study microstructural and compositional aspects of the interface. Nano-indentation tests under static and dynamic loading have also been performed for mechanical strength characterization. It has been found that uniform interfaces with verifiable diffusion are obtainable, with the pouring temperature being the most influential parameter (percentage contribution 92.84%) in this pressure regime. The experiments performed at optimum conditions of pouring temperature, applied pressure and holding time produced a ~328% thicker interface layer, 19.42% better nano-hardness and a 19.10% improved cooling rate as compared to the minimum input values of the said parameters.

Pressure Assisted Development and Characterization of Al-Fe Interface for bi-metallic Composite Castings: An Experimental and Statistical Investigation for Low Pressure Regime

2021 ◽  
Author(s):  
Tayyiba Rashid ◽  
Muhammad Qaiser Saleem ◽  
Nadeem Ahmad Mufti ◽  
Noman Asif ◽  
Kashif Ishfaq ◽  
...  
Keyword(s):  
Optimization Technique ◽  
Low Pressure ◽  
Interface Layer ◽  
Statistical Investigation ◽  
Process Conditions ◽  
Pouring Temperature ◽  
Aluminum Composite ◽  
Indentation Tests ◽  
Strength Characterization ◽  
Pressure Regime

Abstract Review of the available literature indicates that development of metal reinforced castings present intriguing prospects but carry inherent challenges owing to differences in thermal coefficients, chemical affinities, diffusion issues and varying nature of intermetallic compounds. It is supported that pressure application during solidification may favorably influence the dynamics of the aforementioned issues, nevertheless, not only certain limitations have been cited but also some pressure and process regimes have not been found to be investigated and optimized. This work employs the pressure-assisted approach for bi-metallic steel reinforced aluminum composite castings at low-pressure regime and thoroughly investigates the role of three process parameters namely pouring temperature (800°C-900°C), pressure (10–20 bars) and holding time (10–20 sec) for producing sound interfaces. Taguchi L9 orthogonal array has been employed as DOE while dominant factors have been determined via ANOVA and Grey relational analysis multi-objective optimization technique. Supplementary analysis through optical micrographs, SEM and EDS has been relied upon to quantify interfacial layer thicknesses and to study microstructural and compositional aspects of the interface. Nano-indentation tests under static and dynamic loading have also been performed for mechanical strength characterization. It has been found that uniform interfaces with verifiable diffusion are obtainable with pouring temperature being the most influential parameter (PCR 92.84%) in this pressure regime. Optimum parameters determined from the work, yield ~ 328% thicker interface layer, 19.42% better nano-hardness and 19.10% improved cooling rate when compared to the process conditions with least parametric levels.

Effect of Pouring Temperature and Holding Time at Semi-Solid Region on the Morphology of Primary Solid Phase in Semi-Solid Slurry

2006 ◽  
Vol 510-511 ◽  
pp. 782-785 ◽  
Author(s):  
Suk Won Kang ◽  
Ki Bae Kim ◽  
Dock Young Lee ◽  
Jung-Hwa Mun ◽  
Eui Pak Yoon
Keyword(s):  
Solid Phase ◽  
Holding Time ◽  
Pouring Temperature ◽  
Solid Region ◽  
Semi Solid

Computer Modeling of an Ion Trap Mass Analyzer, Part I: Low Pressure Regime

2015 ◽  
Vol 26 (12) ◽  
pp. 2115-2124 ◽  
Author(s):  
Dragan Nikolić ◽  
Stojan M. Madzunkov ◽  
Murray R. Darrach
Keyword(s):  
Computer Modeling ◽  
Ion Trap ◽  
Low Pressure ◽  
Mass Analyzer ◽  
Pressure Regime

Effects of Direct Thermal Method Processing Parameters on Mechanical Properties of Semisolid A6061 Feedstock

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
M. F. M. Tajudin ◽  
A. H. Ahmad ◽  
M. M. Rashidi
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Room Temperature ◽  
Processing Parameters ◽  
Holding Time ◽  
Thermal Method ◽  
Pouring Temperature ◽  
Porosity Level ◽  
Experimental Works ◽  
Temperature Water

This paper highlights the effects of pouring temperature and holding time on the mechanical properties of aluminium 6061 semisolid feedstock billets. The semisolid metal feedstock billets were prepared by a direct thermal method (DTM), in which the molten metal was poured into a cylindrical copper mould with a different combination of pouring temperature and holding time before it was solidified in room temperature water. The results show that the sample with pouring temperature slightly above aluminium 6061 liquidus temperature has the lowest porosity, thereby the highest mechanical properties value. The sample with a pouring temperature of 660 °C and holding time of 60 s has the density, tensile strength and hardness properties of 2.701 g/cm3, 146.797 MPa, and 86.5 HV, respectively. Meanwhile, the sample at a pouring temperature of 640 °C and holding time of 20 s has density, tensile strength and hardness properties of 2.527 g/cm3, 65.39 MPa, and 71.79 HV, respectively. The density and fractography tests were conducted to confirm the existence of porosity within the samples. The results from these experimental works suggested that the mechanical properties of DTM semisolid feedstock billet merely depended on processing parameters, which influenced the porosity level within the feedstock billet, thus directly affected their mechanical properties.

The Numerical Simulation about Second Dendrite Spacing of Low Pressure Casting Automobile Aluminum Magnesium Alloy Wheel

2011 ◽  
Vol 189-193 ◽  
pp. 2096-2102 ◽  
Author(s):  
Xin Zhao ◽  
Yan Wei Sui ◽  
Ai Hui Liu ◽  
Fei Fei Wang ◽  
Zhi Sun ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Cooling Water ◽  
Casting Process ◽  
Low Pressure ◽  
Pressure Casting ◽  
Pouring Temperature ◽  
Alloy Wheel ◽  
Preheating Temperature ◽  
Low Pressure Casting ◽  
Cooling Pipes

Using the method of numerical simulation and the AnyCasting software, the simulation for SDAS of Al-Mg alloy wheels for low pressure casting is studied. The simulation model is established and the effects of preheating temperature, melt pouring temperature and cooling water pipes on SDAS in the low pressure casting process was founded. The results show that, SDAS presents linear variation with the increase of preheating temperature and pouring temperature; opened cooling pipes make SDAS smaller. The practice of simulating casting is verified by experiments, and test results and simulation results were consistent.

A Model for Optimizing Material Removal Rate in Low-Pressure CMP: Effects of Pad Porosity and Abrasive Concentration

2008 ◽  
Author(s):  
Dinc¸er Bozkaya ◽  
Sinan Mu¨ftu¨
Keyword(s):  
Material Removal Rate ◽  
Chemical Mechanical Polishing ◽  
Material Removal ◽  
Removal Rate ◽  
Applied Pressure ◽  
Low Pressure ◽  
Mechanical Polishing ◽  
Low K

The necessity to planarize ultra low-k (ULK) dielectrics [1], and the desire to reduce polishing defects leads to use of lower polishing pressures in chemical mechanical polishing (CMP). However, lowering the applied pressure also decreases the material removal rate (MRR), which causes the polishing time for each wafer to increase. The goal of this work is to investigate effects of pad porosity and abrasive concentration on the MRR.

scholarly journals Pressureless and Low-Pressure Synthesis of Microporous Carbon Spheres Applied to CO2 Adsorption

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5328
Author(s):  
Iwona Pełech ◽  
Daniel Sibera ◽  
Piotr Staciwa ◽  
Urszula Narkiewicz ◽  
Robert Cormia
Keyword(s):  
Co2 Adsorption ◽  
Applied Pressure ◽  
Low Pressure ◽  
Spherical Particles ◽  
Co2 Uptake ◽  
Pressure Treatment ◽  
Carbon Spheres ◽  
Potassium Oxalate ◽  
Uniform Size ◽  
Pressure Synthesis

In this work, low-pressure synthesis of carbon spheres from resorcinol and formaldehyde using an autoclave is presented. The influence of reaction time and process temperature as well as the effect of potassium oxalate, an activator, on the morphology and CO2 adsorption properties was studied. The properties of materials produced at pressureless (atmospheric) conditions were compared with those synthesized under higher pressures. The results of this work show that enhanced pressure treatment is not necessary to produce high-quality carbon spheres, and the morphology and porosity of the spheres produced without an activation step at pressureless conditions are not significantly different from those obtained at higher pressures. In addition, CO2 uptake was not affected by elevated pressure synthesis. It was also demonstrated that addition of the activator (potassium oxalate) had much more effect on key properties than the applied pressure treatment. The use of potassium oxalate as an activator caused non-uniform size distribution of spherical particles. Simultaneously higher values of surface area and total pore volumes were reached. A pressure treatment of the carbon materials in the autoclave significantly enhanced the CO2 uptake at 25 °C, but had no effect on it at 0 °C.

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