scholarly journals Microstructural Evaluation and Corrosion Resistance of Semisolid Cast A356 Alloy Processed by Equal Channel Angular Pressing

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 303 ◽  
Author(s):  
Mohamed Gebril ◽  
Mohd Omar ◽  
Intan Mohamed ◽  
Norinsan Othman
Keyword(s):  
Corrosion Resistance ◽  
Equal Channel Angular Pressing ◽  
Cast Alloy ◽  
A356 Alloy ◽  
Cooling Slope ◽  
Angular Pressing ◽  
Ecap Process ◽  
Heat Treated ◽  
Microstructural Evaluation ◽  
Cooling Slope Casting

As-cast and semisolid casting using a cooling slope A356 alloy were processed by equal channel angular pressing (ECAP) for Si and grain refinement. The ECAP was conducted at room temperature in a mold, with a channel angle of 120°, and this resulted in a significant size reduction of grain and Si particles from 170.5 and 4.22 to 23.12 and 0.71 µm, respectively, after six passes of heat-treated cooling slope casting, using the ECAP process. The hardness increased with ECAP processing, from 61 HV, for the as-cast alloy, to 134 Hv, after six passes of heat-treated cooling slope casting. The corrosion resistance of the alloy improved, from 0.042 to 0.0012 mmy−1, after the ECAP process. In this work both the strength and corrosion resistance of the ECAPed A356 alloys were improved with the application of the cooling slope process than without (i.e., from the as-cast condition).

scholarly journals Microstructure and Properties of Mg-Zn-Y Alloy Powder Compacted by Equal Channel Angular Pressing

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1678 ◽  
Author(s):  
Chun Chiu ◽  
Hong-Min Huang
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Equal Channel Angular Pressing ◽  
Volume Fraction ◽  
Cast Alloy ◽  
Milled Powder ◽  
Microstructural Characterization ◽  
Compressive Yield Strength ◽  
Lpso Phase ◽  
Angular Pressing

Mg97Zn1Y2 (at %) alloy with a long period stacking ordered (LPSO) phase has attracted a great deal of attention due to its excellent mechanical properties. It has been reported that this alloy could be fabricated by warm extrusion of rapid solidified alloy powders. In this study, an alternative route combining mechanical milling and equal channel angular pressing (ECAP) was selected to produce the bulk Mg97Zn1Y2 alloy. Microstructural characterization, mechanical properties and corrosion behavior of the ECAP-compacted alloys were studied. The as-cast alloy contained α-Mg and LPSO-Mg12Zn1Y1 phase. In the as-milled powder, the LPSO phase decomposed and formed Mg24Y5 phase. The ECAP-compacted alloy had identical phases to those of the as-milled sample. The compacted alloy exhibited a hardness of 120 HV and a compressive yield strength of 308 MPa, which were higher than those of the as-cast counterpart. The compacted alloy had better corrosion resistance, which was attributed to the reduced volume fraction of the secondary phase resulting in lower microgalvanic corrosion in the compacted alloy. The increase in Y content in the α-Mg matrix also contributed to the improvement of corrosion resistance.

Effect of Equal Channel Angular Pressing on the Pitting Corrosion Resistance on the Aluminum Alloys with/without Anodization

2010 ◽  
Vol 638-642 ◽  
pp. 1989-1994 ◽  
Author(s):  
Hiroaki Nakano ◽  
In Joon Son ◽  
Satoshi Oue ◽  
Shigeo Kobayashi ◽  
Hisaaki Fukushima ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Equal Channel Angular Pressing ◽  
Pitting Corrosion ◽  
Formation Rate ◽  
Oxide Films ◽  
Mg Alloy ◽  
Angular Pressing ◽  
Ecap Process ◽  
Pitting Corrosion Resistance ◽  
Al Oxide

The effect of equal-channel angular pressing (ECAP) on the pitting corrosion resistance of Al (AA1100) and Al-Mg (AA5052) alloy with anodization and without was investigated by means of polarization curves in solutions containing 300 ppm or 0.6 mol/L of Cl- and by surface analysis. In Al and Al-Mg alloy without anodization, the potentials for pitting corrosion were evidently shifted to the noble direction by ECAP process, indicating that this process improves resistance to pitting corrosion. SEM observation revealed that the pitting corrosion occurred near the impurity precipitates and the size of impurity precipitated decreased with ECAP process. The time-dependence of corrosion potential and the polarization resistance determined by AC impedance technique suggested that the formation rate of Al oxide films was increased with ECAP process. The improvement in pitting corrosion resistance of Al and Al-Mg by ECAP seems to be attributable to the decrease in the size of impurity precipitates and the increase in the formation rate of Al oxide films. On the other hand, the time required for initiating pitting corrosion of anodised Al was longer with ECAP than without, indicating improvement in the pitting corrosion resistance by application of ECAP. However, the pitting corrosion of anodized Al-Mg alloy occurred earlier with ECAP than without, showing that the corrosion resistance was worse with ECAP than without. In anodized Al-Mg alloy, cracks occurred in the anodic oxide films during initial corrosion and the cracks were larger with ECAP than without. It is assumed that the pitting corrosion was promoted by the cracks due to the higher internal stress resulting from ECAP.

Ageing Characteristics of Equal Channel Angular Pressed Al-Mg-Si Alloy

2013 ◽  
Vol 858 ◽  
pp. 3-6 ◽  
Author(s):  
Soon Vern Yee ◽  
Zuhailawati Hussain ◽  
Abu Seman Anasyida ◽  
Muhammad Syukron ◽  
Indra Putra Almanar
Keyword(s):  
Cast Alloy ◽  
Ageing Time ◽  
Applied Strain ◽  
Artificial Ageing ◽  
Maximum Hardness ◽  
Angular Pressing ◽  
Ecap Process ◽  
Α Phase ◽  
Heat Treated ◽  
Alloy 6061

This study investigated the effect of severe plastic deformation (SPD) and artificial ageing treatment on mechanical properties of cast Al-Mg-Si alloy. 6061-T6 aluminum alloy was remelted and casted into a rod of 13mm in diameter and 60mm in length. The rod samples were then subjected to equal channel angular pressing (ECAP) for SPD process, up to 2 passes, through Bc route. Cast and ECAPed samples were solution heat treated at 530 °C, quenched in water and held at 180 °C at various ageing time to determine the effect of artificial ageing. Cast alloy consisted of α phase grains that were surrounded by Mg2Si particles locating at the grain boundaries. The hardness increased with accumulative applied strain by 2-pass ECAP process with the value of 99.4 Hv. For heat treated samples, maximum hardness was achieved after 5-hour ageing.

scholarly journals Microstructural Evolution, Hardness, and Strengthening Mechanisms in SLM AlSi10Mg Alloy Subjected to Equal-Channel Angular Pressing (ECAP)

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7598
Author(s):  
Przemysław Snopiński ◽  
Anna Woźniak ◽  
Marek Pagáč
Keyword(s):  
Electron Microscope ◽  
Equal Channel Angular Pressing ◽  
Weight Ratio ◽  
High Strength ◽  
Melting Process ◽  
Heat Treated Sample ◽  
Aerospace Applications ◽  
Angular Pressing ◽  
Ecap Process ◽  
Heat Treated

The AlSi10Mg alloy is characterized by a high strength-to-weight ratio, good formability, and satisfying corrosion resistance; thus, it is very often used in automotive and aerospace applications. However, the main limitation of using this alloy is its low yield strength and ductility. The equal-channel angular pressing is a processing tool that allows one to obtain ultrafine-grained or nanomaterials, with exceptional mechanical and physical properties. The purpose of the paper was to analyze the influence of the ECAP process on the structure and hardness of the AlSi10Mg alloy, obtained by the selective laser melting process. Four types of samples were examined: as-fabricated, heat-treated, and subjected to one and two ECAP passes. The microstructure analysis was performed using light and electron microscope systems (scanning electron microscope and transmission electron microscope). To evaluate the effect of ECAP on the mechanical properties, hardness measurements were performed. We found that the samples that underwent the ECAP process were characterized by a higher hardness than the heat-treated sample. It was also found that the ECAP processing promoted the formation of structures with semicircular patterns and multiple melt pool boundaries with a mean grain size of 0.24 μm.

Effect of Equal-Channel Angular Pressing on the Pitting Corrosion Resistance of Al Alloy

2006 ◽  
Vol 503-504 ◽  
pp. 487-492 ◽  
Author(s):  
In-Joon Son ◽  
Hiroaki Nakano ◽  
Satoshi Oue ◽  
Shigeo Kobayashi ◽  
Hisaaki Fukushima ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Equal Channel Angular Pressing ◽  
Pitting Corrosion ◽  
Formation Rate ◽  
Electrochemical Techniques ◽  
Mg Alloy ◽  
Al Alloy ◽  
Angular Pressing ◽  
Ecap Process ◽  
Pitting Corrosion Resistance

The effect of equal-channel angular pressing (ECAP) on the pitting corrosion resistance of Al and Al-Mg alloy was investigated by means of polarization curves in solutions containing 300 ppm of Cl- and by surface analysis. The potentials for pitting corrosion of Al and Al-Mg alloy were evidently shifted to the noble direction by using the ECAP process, indicating that this process improves resistance to pitting corrosion. This increase in resistance seems to be attributable to the increase in formation rate of Al oxide films due to the increase in grain boundary with ECAP. The pitting corrosion resistance of Al and Al-Mg alloy anodized galvanostatically in H2SO4 solution after ECAP was also investigated using electrochemical techniques. The pitting corrosion resistance of Al and Al-Mg alloy was remarkably improved by anodizing. However, the pitting corrosion resistance of anodized Al-Mg alloy was better without ECAP than with ECAP.

Mechanical, Metallurgical Characteristics and Corrosion Properties of Equal Channel Angular Pressing of Duplex Stainless Steel

2013 ◽  
Vol 717 ◽  
pp. 9-14 ◽  
Author(s):  
P.M. Ajith ◽  
P. Sathiya ◽  
Kondaiah Gudimetla ◽  
B. Ravishankar
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Duplex Stainless Steel ◽  
Equal Channel Angular Pressing ◽  
Corrosion Properties ◽  
Microstructure Change ◽  
Angular Pressing ◽  
Ecap Process ◽  
Pitting Corrosion Resistance

Duplex Stainless Steel (DSS) is well known for their higher mechanical strength and better corrosion resistance. DSS is commonly used for marine construction, petrochemical and chemical industries. DSS (2205) is having equal amount of α and γ phases.The present study was conducted on12mm diameter rod of the UNS S32205 duplex stainless steel subjected to equal channel angular pressing (ECAP). The refinement of original grains was observed. Effect of microstructure change on the corrosion behavior of equal channel angular pressed (ECAP) UNS S32205 duplex stainless steel was investigated. After single pass ECAP process and study about the pitting corrosion resistance. The mechanical properties of UNS S3 2205 duplex stainless steelwere evaluated. The amount of ferrite after ECAP and before ECAP for the two different conditions was investigated. Also observed percentage of ferrite content reduces 3.32% after ECAP.

Processing of Copper by Equal Channel Angular Pressing (ECAP) – Microstructure Investigations

2015 ◽  
Vol 641 ◽  
pp. 286-293
Author(s):  
Beata Leszczyńska-Madej ◽  
Maria W. Richert ◽  
Agnieszka Hotloś ◽  
Jacek Skiba
Keyword(s):  
Equal Channel Angular Pressing ◽  
Room Temperature ◽  
Subgrain Size ◽  
Pure Copper ◽  
Shear Bands ◽  
Angular Pressing ◽  
Ecap Process ◽  
Transmission Electron ◽  
Different Types ◽  
Diffraction Patterns

The present study attempts to apply Equal-Channel Angular Pressing (ECAP) to 99.99% pure copper. ECAP process was realized at room temperature for 4, 8 and 16 passes through route BC using a die having angle of 90°. The microstructure of the samples was investigated by means both light and transmission electron microscopy. Additionally the microhardness was measured and statistical analysis of the grains and subgrains was performed. Based on Kikuchi diffraction patterns misorientation was determined. There were some different types of bands in the microstructure after deformation. The shear bands, bands and in the submicron range the microshear bands and microbands are a characteristic feature of the microstructure of copper. Also characteristic was increasing of the number of bands with increasing of deformation and mutually crossing of the bands. The intersection of a bands and microbands leads to the formation of new grains with the large misorientation angle. The measured grain/subgrain size show, that the grain size is maintained at a similar level after each stage of deformation and is equal to d = 0.25 – 0.32 μm.

Numerical Simulation of Microstructure Evolution in AZ31 Magnesium Alloy during Equal Channel Angular Pressing

2014 ◽  
Vol 609-610 ◽  
pp. 495-499
Author(s):  
Guo Cheng Ren ◽  
Xiao Juan Lin ◽  
Shu Bo Xu
Keyword(s):  
Finite Element ◽  
Magnesium Alloy ◽  
Equal Channel Angular Pressing ◽  
Microstructure Evolution ◽  
Element Model ◽  
Az31 Magnesium Alloy ◽  
Angular Pressing ◽  
Ecap Process ◽  
Element Simulation ◽  
3D Software

The microstructure and material properties of AZ31 magnesium alloy are very sensitive to process parameters, which directly determine the service properties. To explore and understand the deformation behavior and the optimization of the deformation process, the microstructure evolution during equal channel angular pressing was predicted by using the DEFORM-3D software package at different temperature. To verify the finite element simulation results, the microstructure across the transverse direction of the billet was measured. The results show that the effects strain and deformation temperatures on the microstructure evolution of AZ31 magnesium during ECAP process are significant, and a good agreement between the predicted and experimental results was obtained, which confirmed that the derived dynamic recrystallization mathematical models can be successfully incorporated into the finite element model to predict the microstructure evolution of ECAP process for AZ31 magnesium.

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