Mechanical and corrosion resistance properties of AA7075-T6 sub-zero formed sheets

2021 ◽  
Author(s):  
Rachele Bertolini ◽  
Enrico Simonetto ◽  
Luca Pezzato ◽  
Alberto Fabrizi ◽  
Andrea Ghiotti ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Corrosion Resistance ◽  
Ultimate Tensile Strength ◽  
Uniform Elongation ◽  
Tensile Tests ◽  
High Deformation ◽  
Aerospace Applications ◽  
Before And After ◽  
Forming Temperature ◽  
Manufacturing Process Chain

AbstractThe poor formability of 7xxx series aluminium alloys represents the major limit to their actual use for automotive and aerospace applications. In the present study, the forming temperature effect on the mechanical, corrosion and anodization behaviours of the AA7075-T6 alloy is investigated. To this purpose, tensile tests at different temperatures, ranging from −100 to 300°C, were carried out at different rolling directions. A 6.6% increase of the ultimate tensile strength and a 28.6% increase of the uniform elongation were registered for the specimens deformed at the lowest temperature compared to highest ones. Further, the corrosion resistance of specimens deformed at ultimate tensile strength before and after anodization was increased of 85% and 95%, respectively, compared to the specimens deformed at 300°C. It was demonstrated that high deformation temperatures led to the coalescence of particles and precipitates as well as the decrease of dislocation density, which, in turn, decreased the mechanical and corrosion performances. On the contrary, the deformation temperature of −100°C was found to be the ideal one able to shorten the manufacturing process chain and improve material formability and durability during its in-service life.

scholarly journals Microstructure and Mechanical Properties of Pure Magnesium Subjected to Hot Extrusion

2018 ◽  
Vol 2 (1) ◽  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Work Hardening ◽  
Uniform Elongation ◽  
Hot Extrusion ◽  
Pure Magnesium ◽  
Microstructure And Mechanical Properties ◽  
Before And After

The as-cast pure magnesium (Mg), with a purity of 99.99%, was hot-extruded at 300 o C to prepare a Mg bar with a diameter of 8 mm. The microstructure and mechanical properties of the sample before and after extrusion weis obviously refined with a large number of subgrains rather than equre investigated. The results show that the asextruded microstructure iaxed grains. (10 1 2) tensile twins can be observed significantly in the microstructure at this temperature. Mechanical properties including yield strength (YS), ultimate tensile strength (UTS) increased greatly but uniform elongation (UE) decreased slightly as a result of work hardening.

scholarly journals Microstructural Characterization of Laser Weld of Hot-Stamped Al-Si Coated 22MnB5 and Modification of Weld Properties by Hybrid Welding

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3943
Author(s):  
Hana Šebestová ◽  
Petr Horník ◽  
Šárka Mikmeková ◽  
Libor Mrňa ◽  
Pavel Doležal ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Fusion Zone ◽  
Microstructural Characterization ◽  
Tensile Tests ◽  
Laser Weld ◽  
Martensitic Microstructure ◽  
Laser Welds ◽  
Weld Properties ◽  
Weld Fusion Zone

The presence of Al-Si coating on 22MnB5 leads to the formation of large ferritic bands in the dominantly martensitic microstructure of butt laser welds. Rapid cooling of laser weld metal is responsible for insufficient diffusion of coating elements into the steel and incomplete homogenization of weld fusion zone. The Al-rich regions promote the formation of ferritic solid solution. Soft ferritic bands cause weld joint weakening. Laser welds reached only 64% of base metal's ultimate tensile strength, and they always fractured in the fusion zone during the tensile tests. We implemented hybrid laser-TIG welding technology to reduce weld cooling rate by the addition of heat of the arc. The effect of arc current on weld microstructure and mechanical properties was investigated. Thanks to the slower cooling, the large ferritic bands were eliminated. The hybrid welds reached greater ultimate tensile strength compared to laser welds. The location of the fracture moved from the fusion zone to a tempered heat-affected zone characterized by a drop in microhardness. The minimum of microhardness was independent of heat input in this region.

scholarly journals MICROSTRUCTURE RESEARCH OF THE UNIDIRECTIONAL ORGANOPLASTIC BASED ON RUSAR-NT ARAMID FIBERS AND EPOXY-POLYSULFONE BINDER

2020 ◽  
pp. 19-26
Author(s):  
E.N. Kablov ◽  
◽  
G.S. Kulagina ◽  
G.F. Zhelezina ◽  
S.L. Lonskii ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Composite Material ◽  
Polymer Matrix ◽  
Packing Density ◽  
Tensile Tests ◽  
Polymer Composite Material ◽  
Aramid Fibers ◽  
Before And After ◽  
Binder Structure

This paper studies a polymer composite material - a unidirectional organoplastic based on Rusar-NT aramid fiber and a melt epoxy-polysulfone binder. Organoplastic has the following mechanical properties: tensile strength 2060 MPa, Young's modulus 101 GPa. The microstructure of the fiber and the polymer matrix in the organoplastic samples was studied before and after tensile tests. The features of the formation of the binder structure depending on the packing density of the fibers in organoplastics have been determined. The nature of the destruction of fibers and polymer matrix caused by the uniaxial tension has been studied.

Tensile Properties and Fracture Behavior of SiCp/AC4CH Composite at Loading Velocities of up to 10m/s

2004 ◽  
Vol 449-452 ◽  
pp. 305-308
Author(s):  
Lei Wang ◽  
Toshiro Kobayashi ◽  
Chun Ming Liu
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Tensile Test ◽  
Strain Rate ◽  
Fracture Behavior ◽  
Tensile Deformation ◽  
Optical Microscope ◽  
Fracture Elongation ◽  
Before And After

Tensile test at loading velocities up to 10 m·s-1(strain rate up to 3.2x102s-1) was carried out forr SiCp/AC4CH composite and AC4CH alloy. The microstructure of the composite before and after tensile deformation was carefully examined with both optical microscope and SEM. The experimental results demonstrated that the ultimate tensile strength (UTS) and yield strength (YS) increase with increasing loading velocity up to 10 m·s-1. Comparing with AC4CH alloy, the fracture elongation of the composite is sensitivity with the increasing strain rate. The YS of both the composite and AC4CH alloy shows more sensitive than that of the UTS with the increasing strain rate, especially in the range of strain rate higher than 102s-1.

Thickness-Dependent Tensile Behavior of Cu-Mn Alloys under Different Dislocation Slip Modes

2019 ◽  
Vol 294 ◽  
pp. 104-110 ◽  
Author(s):  
Le Le Kang ◽  
Dong Han ◽  
Xiao Wu Li
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Size Effect ◽  
Uniform Elongation ◽  
Tensile Behavior ◽  
Dislocation Slip ◽  
Slip Mode ◽  
Planar Slip ◽  
Metallic Materials

To explore the role of dislocation slip mode playing in the size effect of mechanical behavior of metallic materials, the tensile behavior of Cu-5at.%Mn and Cu-20at.%Mn alloys with thickness (t) spanning from 0.1 to 2.0 mm is investigated. The results reveal that the yield strength σYS of Cu-5at.%Mn alloy displays an independence of thickness, whereas the ultimate tensile strength σUTS and the uniform elongation δ show an obvious size effect. The σUTS and δ first slightly decrease as t is reduced from 2.0 to 0.5 mm, but evidently drop when t is below 0.5 mm. A similar size effect is also exhibited in Cu-20at.%Mn alloy; however, the variation trend of “the smaller the weaker” in size effect can be weakened by the planar slip of dislocations occurring during the deformation of this alloy.

Tensile Tests for Cast Stainless Steel: Evolution of the RCC-M Code

2018 ◽  
Author(s):  
Arnaud Blouin ◽  
Mathieu Couvrat ◽  
Félix Latourte ◽  
Julian Soulacroix
Keyword(s):  
Tensile Strength ◽  
Stainless Steel ◽  
Ultimate Tensile Strength ◽  
Tensile Tests ◽  
Pressurized Water Reactor ◽  
Pressurized Water ◽  
Different Diameters ◽  
Cast Stainless Steel ◽  
Acceptance Tests ◽  
Do So

In the framework of a pressurized water reactor primary loop replacement, elbows of different types were produced in cast austenitic stainless steel grade Z3CN 20-09 M. For that type of component, acceptance tests to check the sufficient mechanical properties include room and hot temperature tensile tests, following the RCC-M CMS – 1040 and EN 10002 specifications. A large test campaign on standard 10mm diameter specimens was performed and exhibited a high scattering in yield stress and ultimate tensile strength values. As a consequence, some acceptance tensile tests failed to meet the required minimal values, especially the ultimate tensile strength. Optical and electronic microscopy revealed that the low values were due to the presence of very large grain compared to the specimen gage diameter. However, tensile tests strongly rely on the hypothesis that the specimen gage part can be considered as a representative volume element containing a number of grains large enough so that their variation in size and orientation gives a homogeneous response. To confirm the origin of the scattering, a huge experimental tensile test campaign with specimens of different diameters was conducted. In parallel, FE calculations were also performed. From all those results, it was concluded that it was necessary to improve the RCC-M code for that type of test for cast stainless steel: to do so, a modification sheet was sent and is being investigated by AFCEN.

scholarly journals Investigation of Electroplastic Effect on Four Grades of Duplex Stainless Steels

Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 1911 ◽  
Author(s):  
Claudio Gennari ◽  
Luca Pezzato ◽  
Enrico Simonetto ◽  
Renato Gobbo ◽  
Michele Forzan ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Stress ◽  
Stainless Steels ◽  
Uniform Elongation ◽  
Electrical Current ◽  
Total Elongation ◽  
Duplex Stainless Steels ◽  
Electroplastic Effect ◽  
Two Phases

Since the late 1950s, an effect of electrical current in addition to joule heating on the deformation of metals called the Electroplastic Effect (EPE) has been known. It is used nowadays in the so-called Electrically Assisted Forming (EAF) processes, but the understanding of the phenomenon is not very clear yet. It has been found that EPE increases the formability of high stacking fault energy (SFE) materials, while low SFE materials reach fracture prematurely. Since Duplex Stainless Steels (DSSs) possess a microstructure consisting of two phases with very different SFE (low SFE austenite and high SFE ferrite) and they are widely used in industry, we investigated EPE on those alloys. Tensile tests at 5 A/mm2, 10 A/mm2 and 15 A/mm2 current densities along with thermal counterparts were conducted on UNS S32101, UNS S32205, UNS S32304 and UNS S32750. The DSS grades were characterized by means of optical microscopy, X-ray diffraction and their mechanical properties (ultimate tensile strength, total elongation, uniform elongation and yield stress). An increase in uniform elongation for the electrical tests compared to the thermal counterparts as well as an increase in total elongation was found. No differences were observed on the yield stress and on the ultimate tensile strength. Un uneven distribution of the current because of the different resistivity and work hardening of the two phases has been hypothesized as the explanation for the positive effect of EPE.

Mechanical Properties and Fracture Study of Alumina Dispersion Hardened Copper-Based Nano-Composite at Elevated Temperatures

2013 ◽  
Vol 829 ◽  
pp. 583-588 ◽  
Author(s):  
Ali Dalirbod ◽  
Yahya A. Sorkhe ◽  
Hossein Aghajani
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Fracture Surface ◽  
Yield Strength ◽  
Elevated Temperatures ◽  
Tensile Tests ◽  
Testing Temperature ◽  
Optical Microscope ◽  
Tensile Fracture ◽  
Different Temperatures

Alumina dispersion hardened copper-base composite was fabricated by internal oxidation method. The high temperature tensile fracture of Cu-Al2O3 composite was studied and tensile strengths were determined at different temperatures of 600, 680 and 780 °C. Microstructure was investigated by means of optical microscope and field emission scanning electron microscope (FESEM) with energy dispersive spectroscopy (EDS). Results show that, ultimate tensile strength and yield strength of copper alumina nanocomposite decrease slowly with increasing temperature. The yield strength reaches 119 MPa and ultimate tensile strength reaches 132 MPa at 780 °C. Surface fractography shows a dimple-type fracture on the fracture surface of the tensile tests where dimple size increases with increasing testing temperature and in some regions brittle fracture characteristics could be observed in the fracture surface.

scholarly journals Effect of welding sequence and welding current on distortion, mechanical properties and metallurgical observations of orbital pipe welding on SS 316L

2021 ◽  
Vol 2 (12 (110)) ◽  
pp. 22-31
Author(s):  
Agus Widyianto ◽  
Ario Sunar Baskoro ◽  
Gandjar Kiswanto ◽  
Muhamad Fathin Ginanjar Ganeswara
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Welding Process ◽  
Welding Current ◽  
Tensile Tests ◽  
Welding Parameters ◽  
Depth Of Penetration ◽  
Welding Sequence ◽  
Pipe Welding

Orbital pipe welding was often used to manufacture piping systems. In orbital pipe welding, a major challenge is the welding torch’s position during the welding process, so that additional methods are needed to overcome these challenges. This paper discusses the influence of welding sequence and welding current on distortion, mechanical properties and metallurgical observations in orbital pipe welding with SS 316L pipe square butt joints. The variation of the orbital pipe welding parameters used is welding current and welding sequence. The welding current used is 100 A, 110 A, and 120 A, while the welding sequence used is one sequence, two sequences, three sequences, and four sequences. The welding results will be analyzed from distortion measurement, mechanical properties test and metallurgical observations. Distortion measurements are made on the pipe before welding and after welding. Testing of mechanical properties includes tensile tests and microhardness tests, while metallurgical observations include macrostructure and microstructural observations. The results show that maximum axial distortion, transverse distortion, ovality, and taper occurred at a welding current of 120 A with four sequences of 445 µm, 300 µm, 195 µm, and 275 µm, respectively. The decrease in ultimate tensile strength is 51 % compared to the base metal’s ultimate tensile strength. Horizontal and vertical microhardness tests show that welding with one sequence produces the greatest microhardness value, but there is a decrease in the microhardness value using welding with two to four sequences. Orbital pipe welding results in different depths of penetration at each pipe position. The largest and smallest depth of penetration was 4.11 mm and 1.60 mm, respectively

scholarly journals Mechanical and tribological behavior of Al composites containing varying beryllium aluminum silicate and constant CeO2

2021 ◽  
Vol 3 (10) ◽  
Author(s):  
Vikas Verma ◽  
Ronaldo Câmara Cozza ◽  
Vladimir Cheverikin ◽  
Alexander Kondratiev ◽  
Ramkumar Penchaliah
Keyword(s):  
Tensile Strength ◽  
Corrosion Resistance ◽  
Ultimate Tensile Strength ◽  
High Hardness ◽  
Stir Casting ◽  
Aluminum Silicate ◽  
List Type ◽  
Structural Applications ◽  
Sem Micrograph ◽  
Characteristic Features

Abstract The main aim of the present work is to see the performance of “Al–Beryl” composites processed via stir casting route with or without CeO2 on their mechanical, wear and corrosive properties for structural applications in heavy machinery and watercrafts. Hardness and ultimate tensile strength increased with 36% and 43%, respectively, with 9% Beryl addition. Further, effect of addition of constant 0.5 wt.% CeO2 in “Al–Beryl” composite was evaluated and remarkably improvement in corrosion resistance was observed. Tribological performance of the composites was investigated by conducting sliding wear tests against steel at different loads in dry and wet conditions. Characteristic features of adhesion, fracture and delamination were observed in SEM micrograph of the worn composite having low beryl content slid in air whereas abrasive wear predominates in water or oil. Addition of increased wt.% of beryl particles led in reduced wear of the composite at all loads. Increase in corrosion resistance by 45% decrease in weight loss with 0.5% CeO2 addition was observed. “Al6061–9% Beryl–0.5% CeO2” composite with high hardness, wear and corrosion resistance is found most promising for structural applications. Article Highlights An increase of 36% in hardness and 43% in ultimate tensile strength was found in Al composites with 9% Beryl addition; Coefficient of friction was found least for “Beryl–CeO2” added composites in wet sliding conditions; A transition in wear mechanism occurred with adhesion, fracture and delamination of the worn composite with low beryl content slid in air; Corrosion resistance increased by 45% with 0.5% CeO2 addition in Al composites.

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