Effect of warm equal channel angular pressing on the structure and mechanical properties of Ti0.16Pd0.14Fe (wt%) alloy

Abstract Here we analyze the microstructure and phase composition of a Ti alloy with 0.16Pd and 0.14Fe (wt%) alloy exposed to warm equal channel angular pressing (ECAP) at 648 K. The analysis shows that after four ECAP passes, the material assumes a submicrocrystalline structure with an average grain size of 0.28 μm, as against its initial value 10 μm, and that the α phase dominates in the alloy both before and after ECAP. The initial alloy reveals a high content of Fe and Pd atoms near grain boundaries compared to central grain regions. Such near-boundary zones contain orthorhombic α′′ martensite in addition to the α phase, and β or α + β particles are found directly at the grain boundaries. These features of the phase composition are inherited after ECAP. The yield strength of the ECAP treated alloy is 500 MPa, being greater than the initial strength 350 MPa, and its margin of plasticity is rather high. The torsional strain up to fracture in the initial and in the ECAP treated alloy is 70% and 50%, respectively.

Download Full-text

Microstructure and Properties of Cu-5.7%Cr In Situ Fibrous Composite Produced by Equal-Channel Angular Pressing and Cold Rolling

Materials Science Forum ◽

10.4028/www.scientific.net/msf.667-669.541 ◽

2010 ◽

Vol 667-669 ◽

pp. 541-546 ◽

Cited By ~ 2

Author(s):

Wei Wei ◽

Fei Wang ◽

Kun Xia Wei ◽

Igor V. Alexandrov ◽

Jing Hu

Keyword(s):

Electrical Conductivity ◽

Tensile Strength ◽

Cold Rolling ◽

Equal Channel Angular Pressing ◽

Cast Alloy ◽

Fibrous Composite ◽

Angular Pressing ◽

Average Grain Size ◽

Before And After

The composite filament structure was produced in Cu-5.7%Cr as-cast alloy ingots, subjected to equal channel angular pressing (ECAP) and cold rolling (CR) at room temperature. Microstructure, tensile properties and electrical conductivity before and after the severe plastic deformation (SPD) processing have been investigated here. The results point out that the rotation and spreading of Cr particles took place during ECAP and the additional rolling resulting in long thin in situ filaments. The average grain size of a Cu phase is equal to about 200 nm after eight ECAP passes. The formation of finer equiaxed grains of the Cu phase has been revealed after the additional CR. The tensile strength 403 MPa and 507 MPa have been achieved after one and eight ECAP passes respectively and increased up to 517 MPa and 607 MPa after the subsequent CR deformation. The enhancement of the tensile strength and the deterioration of the electrical conductivity have been explained by the microstructure evolution of Cu matrix and the dendritic Cr phase.

Download Full-text

Grain boundary structure in Al–Mg and Al–Mg–Sc alloys after equal-channel angular pressing

Journal of Materials Research ◽

10.1557/jmr.2001.0084 ◽

2001 ◽

Vol 16 (2) ◽

pp. 583-589 ◽

Cited By ~ 54

Author(s):

Keiichiro Oh-ishi ◽

Zenji Horita ◽

David J. Smith ◽

Terence G. Langdon

Keyword(s):

Grain Boundaries ◽

Equal Channel Angular Pressing ◽

High Pressure Torsion ◽

High Resolution Electron Microscopy ◽

High Energy ◽

Boundary Structure ◽

Angular Pressing ◽

Grain Boundary Structure ◽

Resolution Electron ◽

Before And After

Samples of an Al–3% Mg alloy and an Al–3% Mg–0.2% Sc alloy were subjected to equal-channel angular pressing (ECAP) to reduce the grain size to approximately 0.2–0.3 μm. Some samples of each alloy were also annealed for 1 h at temperatures of either 423 or 673 K, respectively. High-resolution electron microscopy was used to examine the microstructure both before and after annealing. The grain boundaries after ECAP were wavy and faceted and in high-energy nonequilibrium configurations. These results were consistent with earlier observations of materials subjected to severe plastic deformation using high-pressure torsion. In addition, some grain boundaries in the Al–Mg–Sc alloy had a zigzag appearance after annealing at 673 K, where the straight portions of the boundary were identified as low-energy {111} planes. It is suggested these are mobile boundaries lying in a lowest energy configuration where mobility may be restricted by the presence of incoherent Al3Sc particles.

Download Full-text

Effects of equal channel angular pressing and heat treatments on the microstructures and mechanical properties of selective laser melted and cast AlSi10Mg alloys

Archives of Civil and Mechanical Engineering ◽

10.1007/s43452-021-00246-y ◽

2021 ◽

Vol 21 (3) ◽

Author(s):

Przemysław Snopiński ◽

Mariusz Król ◽

Marek Pagáč ◽

Jana Petrů ◽

Jiří Hajnyš ◽

...

Keyword(s):

Mechanical Properties ◽

Low Temperature ◽

Equal Channel Angular Pressing ◽

Heat Treatments ◽

Electron Backscattered Diffraction ◽

Angular Pressing ◽

Low Temperature Annealing ◽

Transmission Electron ◽

Before And After ◽

The Impact

AbstractThis study investigated the impact of the equal channel angular pressing (ECAP) combined with heat treatments on the microstructure and mechanical properties of AlSi10Mg alloys fabricated via selective laser melting (SLM) and gravity casting. Special attention was directed towards determining the effect of post-fabrication heat treatments on the microstructural evolution of AlSi10Mg alloy fabricated using two different routes. Three initial alloy conditions were considered prior to ECAP deformation: (1) as-cast in solution treated (T4) condition, (2) SLM in T4 condition, (3) SLM subjected to low-temperature annealing. Light microscopy, transmission electron microscopy, X-ray diffraction line broadening analysis, and electron backscattered diffraction analysis were used to characterize the microstructures before and after ECAP. The results indicated that SLM followed by low-temperature annealing led to superior mechanical properties, relative to the two other conditions. Microscopic analyses revealed that the partial-cellular structure contributed to strong work hardening. This behavior enhanced the material’s strength because of the enhanced accumulation of geometrically necessary dislocations during ECAP deformation.

Download Full-text

Experimental and Numerical Investigation of the ECAP Processed Copper: Microstructural Evolution, Crystallographic Texture and Hardness Homogeneity

Metals ◽

10.3390/met11040607 ◽

2021 ◽

Vol 11 (4) ◽

pp. 607

Author(s):

A. I. Alateyah ◽

Mohamed M. Z. Ahmed ◽

Yasser Zedan ◽

H. Abd El-Hafez ◽

Majed O. Alawad ◽

...

Keyword(s):

Grain Size ◽

Equal Channel Angular Pressing ◽

Cross Section ◽

Room Temperature ◽

Pure Copper ◽

High Density ◽

Ecap Processing ◽

Heterogeneous Distribution ◽

Angular Pressing ◽

Average Grain Size

The current study presents a detailed investigation for the equal channel angular pressing of pure copper through two regimes. The first was equal channel angular pressing (ECAP) processing at room temperature and the second was ECAP processing at 200 °C for up to 4-passes of route Bc. The grain structure and texture was investigated using electron back scattering diffraction (EBSD) across the whole sample cross-section and also the hardness and the tensile properties. The microstructure obtained after 1-pass at room temperature revealed finer equiaxed grains of about 3.89 µm down to submicrons with a high density of twin compared to the starting material. Additionally, a notable increase in the low angle grain boundaries (LAGBs) density was observed. This microstructure was found to be homogenous through the sample cross section. Further straining up to 2-passes showed a significant reduction of the average grain size to 2.97 µm with observable heterogeneous distribution of grains size. On the other hand, increasing the strain up to 4-passes enhanced the homogeneity of grain size distribution. The texture after 4-passes resembled the simple shear texture with about 7 times random. Conducting the ECAP processing at 200 °C resulted in a severely deformed microstructure with the highest fraction of submicron grains and high density of substructures was also observed. ECAP processing through 4-passes at room temperature experienced a significant increase in both hardness and tensile strength up to 180% and 124%, respectively.

Download Full-text

Microstructures and Mechanical Properties of AZ61 Mg Alloy Processed by Equal Channel Angular Pressing

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.468-471.2124 ◽

2012 ◽

Vol 468-471 ◽

pp. 2124-2127 ◽

Cited By ~ 1

Author(s):

Shao Feng Zeng ◽

Kai Huai Yang ◽

Wen Zhe Chen

Keyword(s):

Mechanical Properties ◽

Grain Size ◽

Equal Channel Angular Pressing ◽

Uniform Elongation ◽

Considerable Decrease ◽

Angular Pressing ◽

Az61 Magnesium Alloy ◽

Average Grain Size ◽

Microstructures And Mechanical Properties ◽

Bimodal Grain Size

Equal channel angular pressing (ECAP) was applied to a commercial AZ61 magnesium alloy for up to 8 passes at temperatures as low as 473K. Microstructures and mechanical properties of as-received and ECAP deformed samples were investigated. The microstructure was initially not uniform with a “bimodal” grain size distribution but became increasingly homogeneous with further ECAP passes and the average grain size was considerably reduced from over 26 μm to below 5 μm. The ultimate tensile strength (UTS) decreases clearly after one pass, but increases significantly up to two passes, and then continuously slowly decreases up to six passes, and again increases slightly up to eight passes. In contrast, the uniform elongation increased significantly up to 3 passes, followed by considerable decrease up to 8 passes. These observations may be attributed to combined effects of grain refinement and texture development.

Download Full-text

Effect of Deformation Structure and Annealing Temperature on Corrosion of Ultrafine-Grain Fe-Cr Alloy Prepared by Equal Channel Angular Pressing

International Journal of Corrosion ◽

10.1155/2018/4853175 ◽

2018 ◽

Vol 2018 ◽

pp. 1-15

Author(s):

Muhammad Rifai ◽

Motohiro Yuasa ◽

Hiroyuki Miyamoto

Keyword(s):

Grain Boundaries ◽

Equal Channel Angular Pressing ◽

Annealing Temperature ◽

Surface Region ◽

Passivation Layer ◽

Ultrafine Grain ◽

Deformation Structure ◽

Early Stages ◽

Angular Pressing ◽

The Stability

The effect of the deformation structure and annealing temperature on the corrosion of ultrafine-grain (UFG) Fe-Cr alloys with 8 to 12% Cr prepared by equal channel angular pressing (ECAP) was investigated with particular emphasis on the stability of the passivation layer. Fe-Cr alloys were processed by ECAP using up to eight passes at 423 K by the Bc route, followed by annealing at temperatures of 473 to 1173 K for 1 h. Passivity appeared in all alloys as a result of ECAP, and the stability of the passivation layer was evaluated by anodic polarization measurements in a 1000 mol·m−3 NaCl solution. The stability of the passivation layer increased as the degree of deformation became more extensive with successive ECAP passes, and distinct escalation occurred with the formation of a UFG microstructure. In the early stages of annealing at moderate temperatures, the stability of the passivation layer deteriorated, although no visible grain growth occurred, and this effect increased monotonically with increasing annealing temperature. The high degree of stability of the passivation layer on UFG alloys following ECAP can be attributed to the large number of high-angle nonequilibrium grain boundaries, which may lead to Cr enrichment of the surface region. The deterioration of the passivation layer in the early stages of annealing may be attributed to a change in the grain boundaries to an equilibrium state. The present results show that the superiority of as-ECAPed materials of the Fe-Cr alloy to recovered ones by heat treatment can be achieved with 8–10% Cr as observed in 20% Cr.

Download Full-text

Preparation and Mechanical Properties of Ultra-Fine Grain Medium-Carbon Steel Based on Equal-Channel Angular Pressing

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.645-646.427 ◽

2015 ◽

Vol 645-646 ◽

pp. 427-434

Author(s):

Jian Min Wang ◽

Wen Tao Hou ◽

Lin Lu

Keyword(s):

Phase Transformation ◽

Carbon Steel ◽

Equal Channel Angular Pressing ◽

Martensitic Steel ◽

Medium Carbon Steel ◽

Optimal Size ◽

Tempering Temperature ◽

Medium Carbon ◽

Angular Pressing ◽

Average Grain Size

A new technology of preparing submicron medium-carbon steel quickly using martensitic steel by equal-channel angular pressing is developed. The technology combines martensite phase transformation with severe plastic deformation. In this research, martensitic steel is heated to 923K quickly and held for appropriate time, then equal-channel angular pressing is implemented. Supersaturated ferrites of average grain size within 0.5μm are obtained by the interaction of dislocation intersection, dynamic recrystallization and strain-induced phase transformation. At the same time, strain-induced phase transformation leads to dispersive precipitation of supersaturated carbon particles in the form of carbide inside grains or in grain boundaries. The optimal size of ferrite grains and the optimal distribution of carbides are acquired by controlling tempering temperature and time. The results show that ultra-fine grained materials prepared by this technology possess superior thermal stability.

Download Full-text

Grain Refinement of Copper Alloys by Equal Channel Angular Pressing

Materials Science Forum ◽

10.4028/www.scientific.net/msf.449-452.177 ◽

2004 ◽

Vol 449-452 ◽

pp. 177-180 ◽

Cited By ~ 4

Author(s):

Cha Yong Lim ◽

Jae Hyuck Jung ◽

Seung Zeon Han

Keyword(s):

Grain Size ◽

Equal Channel Angular Pressing ◽

Copper Alloys ◽

Metallic Materials ◽

Fine Grained ◽

Angular Pressing ◽

Fine Grain ◽

Transmission Electron ◽

Ultrafine Grained ◽

Average Grain Size

The equal channel angular pressing (ECAP) is one of the methods to refine the grain size of metallic materials. This study investigates the effect of ECAP process on the formation of the fine grain size in oxygen free Cu and Cu alloys. The average grain size has been refined from 150 µm before ECAP to 300 nm. Microstructure was analyzed by transmission electron micrography (TEM). The diffraction pattern of the selected area confirmed the formation of ultrafine-grained structure with high angle grain boundaries after 8 cycles of ECAP. Mechanical properties such as microhardness and tensile properties of the ultra-fine grained copper materials have been investigated.

Download Full-text

Microstructure and Mechanical Properties of Mg96Y3Zn1 Alloy Processed by Equal Channel Angular Pressing

Materials Science Forum ◽

10.4028/www.scientific.net/msf.682.49 ◽

2011 ◽

Vol 682 ◽

pp. 49-54

Author(s):

Bin Chen ◽

Chen Lu ◽

Dong Liang Lin ◽

Xiao Qin Zeng

Keyword(s):

Mechanical Properties ◽

Grain Size ◽

Tensile Strength ◽

Ultimate Tensile Strength ◽

Yield Strength ◽

Tensile Test ◽

Equal Channel Angular Pressing ◽

Ultrafine Grains ◽

Angular Pressing ◽

Average Grain Size

The Mg96Y3Zn1 alloy processed by equal channel angular pressing has been investigated. It was found that the Mg96Y3Zn1 alloy processed by ECAP obtained ultrafine grains and exhibits excellent mechanical properties. After ECAP, the average grain size of Mg96Y3Zn1 alloy refined to about 400 nm. The highest strengths with yield strength of 381.45MPa and ultimate tensile strength of 438.33MPa were obtained after 2 passes at 623K. It was found that cracks were preferentially initiated and propagated in the interior of X-phase during the tensile test. As a result, the elongation of alloy is decreased with pass number increasing.

Download Full-text

Impact of Equal Channel Angular Pressing on Mechanical Behavior and Corrosion Resistance of Hot-Rolled Ti-2Fe-0.1B Alloy

Materials ◽

10.3390/ma13225117 ◽

2020 ◽

Vol 13 (22) ◽

pp. 5117

Author(s):

Yanhuai Wang ◽

Xin Li ◽

I. V. Alexandrov ◽

Li Ma ◽

Yuecheng Dong ◽

...

Keyword(s):

Grain Size ◽

Corrosion Resistance ◽

Titanium Alloy ◽

Mechanical Behavior ◽

Equal Channel Angular Pressing ◽

Hot Rolling ◽

Low Cost ◽

Angular Pressing ◽

Average Grain Size ◽

Hot Rolled

In the present study, the unique bimodal grain size distribution microstructure with the ultrafine substrate and embedded macro grains was fabricated by a traditional hot-rolling process in a novel low-cost Ti-2Fe-0.1B titanium alloy, which possesses a good combination of strength (around 663 MPa) and ductility (around 30%) without any post heat treatment. Meanwhile, the mechanical behavior and corrosion resistance of hot-rolled Ti-2Fe-0.1B alloy after equal channel angular pressing (ECAP) deformation were studied. Results indicated that the average grain size decreased to 0.24 μm after 4 passes ECAP deformation, which led to the enhancement of tensile strength to around 854 MPa and good ductility to around 15%. In addition, corrosion resistance was also improved after ECAP due to the rapid self-repairing and thicker passivation film. Our study revealed that the novel low-cost titanium alloy after hot-rolling and ECAP could be used instead of Ti-6Al-4V in some industrial applications due to similar mechanical behavior and better corrosion resistance.

Download Full-text