Effect of Electrical Current on Cold Work in Aluminum 2024

2017 ◽  
Author(s):  
Derek Shaffer ◽  
Sean Sehman ◽  
Ihab Ragai ◽  
John T. Roth ◽  
Bin Wang
Keyword(s):  
Heat Treatment ◽  
Residual Stresses ◽  
Tensile Properties ◽  
Current Density ◽  
Material Properties ◽  
Cold Work ◽  
Electrical Current ◽  
Material Microstructure ◽  
Expected Effect ◽  
The Difference

Many manufacturers are looking towards electrical treatments as methods for reducing residual stresses in formed metals. Although many people have investigated the effects electricity has on residual stresses and plasticity, there has not been research investigating the effects it has as a post-treatment on strain hardening. Therefore, the goal of this research is to show the permanent changes in tensile properties that electrical treatments have on strain hardened metals, specifically Aluminum 2024. For this initial investigation, only one pulse duration and current density was used to categorize any changes in the metals due to applying electric current. This testing shows the difference between post-deformation heat treatments and post-deformation electrical treatments. Tensile properties of Aluminum 2024 were used to gauge the changes caused by the treatments. The heat treatment had the expected effect of lower the strength of the material and regrowing the grains while the electrical treatment did not seem to drastically change the structure of the grains, but still lowered the strength of the material. Microstructure investigations also showed that the material does in fact show slight changes in material properties, but no drastic changes in microstructure. These images also show that the regrowth from the heat treatment is clearly the reason for the decrease in strength.

Fatigue in Engine Design

1953 ◽  
Vol 57 (513) ◽  
pp. 580-584
Author(s):  
F. M. Owner
Keyword(s):  
Crystal Structure ◽  
Heat Treatment ◽  
Cold Work ◽  
Controlled Atmosphere ◽  
The Core ◽  
Test Conditions ◽  
Engine Design ◽  
The Difference ◽  
Cylindrical Test ◽  
Effect Of Surface

The difference in outlook between metallurgist, physicist and designer on the problem of fatigue of metals is due not only to the differences in training and method but also in immediate objective, however closely their ultimate objectives may coincide.Physicists consider fatigue in terms of crystal structure and composition of the constituents of the crystal, noting in passing that certain types of crystal structures are associated with poor fatigue strength. The metallurgist's prime interest lies in the effect of surface finish, heat treatment, the physical condition of the surface, such as degree of cold work, the effect of carburised and nitrided cases having different hardness from the core. Both think in terms of controlled condition tests, with idealised test conditions such as cylindrical test specimens, close control of changes of section, polished surfaces of only a few micro-inches surface roughness, operating in a controlled atmosphere.

scholarly journals Through-Thickness Residual Stresses, Microstructure, and Mechanical Properties of Electron Beam-Welded CA6NM Martensitic Stainless Steel after Postweld Heat Treatment

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Sheida Sarafan ◽  
Priti Wanjara ◽  
Jean-Benoît Lévesque ◽  
Javad Gholipour ◽  
Henri Champliaud ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Stainless Steel ◽  
Electron Beam ◽  
Residual Stresses ◽  
Tensile Properties ◽  
Martensitic Stainless Steel ◽  
Postweld Heat Treatment ◽  
Image Correlation ◽  
Postweld Heat

In this study, the integrity of electron beam- (EB-) welded CA6NM—a grade of 13% Cr-4% Ni martensitic stainless steel—was assessed through the entire joint thickness of 90 mm after postweld heat treatment (PWHT). The joints were characterized by examining the microstructure, residual stresses, global mechanical properties (static tensile, Charpy impact, and bend), and local properties (yield strength and strain at fracture) in the metallurgically modified regions of the EB welds. The applied PWHT tempered the “fresh” martensite present in the microstructure after welding, which reduced sufficiently the hardness (<280 HV) and residual stresses (<100 MPa) to meet the requirements for hydroelectric turbine assemblies. Also, the properties of the EB joints after PWHT passed the minimum acceptance criteria specified in ASME sections VIII and IX. Specifically, measurement of the global tensile properties indicated that the tensile strengths of the EB welds in the transverse and longitudinal directions were on the same order as that of the base metal (BM). Evaluation of the local tensile properties using a digital image correlation (DIC) methodology showed higher local yield strengths in the fusion zone (FZ) and heat-affected zone (HAZ) of 727 MPa and 740 MPa, respectively, relative to the BM value of 663 MPa. Also, the average impact energies for the FZ and HAZ were 63 J and 148 J, respectively, and attributed to the different failure mechanisms in the HAZ (dimples) versus the FZ (quasi-cleavage consisting of facets and dimples). This study shows that the application of PWHT plays an important role in improving the weld quality and performance of EB-welded CA6NM and provides the essential data for validating the design and manufacturing process for next-generation hydroelectric turbine products.

Effect of Cooling Rate on the Tensile Yield Strength and Ductility Of B2 Compound in Nb-40at.% Ti-15at.%Al Alloy

1993 ◽  
Vol 322 ◽  
Author(s):  
D.-H. Hou ◽  
H.L. Fraser
Keyword(s):  
Heat Treatment ◽  
Tensile Properties ◽  
Cooling Rate ◽  
Heat Treatments ◽  
Water Quenching ◽  
Tensile Yield Strength ◽  
Dominant Factor ◽  
Al Alloy ◽  
Air Cooling ◽  
The Difference

AbstractThe effect of cooling rate on the tensile properties of specimens of the Nb-40Ti-15A1 alloy (in at.%) subjected to various heat treatments has been studied. This alloy has the B2 crystal structure and an order-disorder transition temperature between 1020°C and 1100°C. Two heat treatments have been carried out; the first one involves an 1100°C/1hr heat treatment followed by furnace cooling, air cooling or water quenching. The second type of heat treatment involves re-heating the furnace-cooled and water-quenched specimens at 400°C for 10 minutes or 900°C for 30 minutes, followed by either furnace cooling or water quenching. Tensile properties, SEM fractographs and microstructures of these specimens have been assessed. It is shown that specimens furnace-cooled from 1100°C have higher strength and less ductility than the water quenched ones. An observed microstructural feature associated with cooling rates is the difference in anti-phase domain (APD) size. Discussions are focused on possible cooling rate related phenomena that could affect the tensile properties. It is proposed that the degree of long range ordering, not the APD size, is the dominant factor for the observed cooling rate effect on the tensile properties.

ALLEGHENY LUDLUM AL 400

Alloy Digest ◽  
1989 ◽  
Vol 38 (9) ◽  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Copper Alloy ◽  
Cold Work ◽  
Heat Treating ◽  
Temperature Performance ◽  
Nickel Copper

Abstract Allegheny Ludlum AL 400 is a ductile nickel-copper alloy with resistance to a variety of corrosive conditions. The alloy is not hardenable by heat treatment. It can be appreciably strengthened by cold work. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, and joining. Filing Code: Ni-374. Producer or source: Allegheny Ludlum Corporation.

The Effects of DC Current on the Tensile Properties of Metals

Materials ◽  
2005 ◽  
Author(s):  
Carl Ross ◽  
John T. Roth
Keyword(s):  
Tensile Properties ◽  
Cold Work ◽  
Electrical Current ◽  
Deformation Energy ◽  
Strain Rates ◽  
Negative Effects ◽  
Alternative Means ◽  
Metallic Specimen ◽  
Current Flows ◽  
Dc Current

When fabricating parts, deformation is commonly conducted in a “warm” or “hot” state in order to reduce the total energy required to form the metal. However, there are several negative effects associated with this method of energy reduction (e.g., high tool/die adhesions, environmental reactivity, etc.) Hence, another more efficient method of reducing the total deformation energy would be very beneficial. This paper examines an alternative means of reducing the energy by applying an electrical current and also determines how the material’s tensile properties are affected while the current is present. Also investigated are the influences of strain rate and cold work on the electrical effects. The stress-strain curves indicate that, when current flows through a metallic specimen, the energy required to cause deformation is greatly decreased; demonstrating that electricity provides a viable alternative to increasing the workpiece temperature. However, the effect of the electricity diminishes with increasing strain rates.

COPPER ALLOY No. C61900

Alloy Digest ◽  
1990 ◽  
Vol 39 (2) ◽  
Keyword(s):  
Heat Treatment ◽  
Physical Properties ◽  
Tensile Properties ◽  
Copper Alloy ◽  
Cold Work ◽  
Heat Treating ◽  
Hot Working ◽  
Aluminum Bronze

Abstract Copper Alloy No. 61900 is an aluminum bronze with nominal 9% aluminum and 3.5% iron. It has excellent hot working characteristics and fair capacity for cold work. It is not hardenable by heat treatment. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fatigue. It also includes information on forming, heat treating, machining, and joining. Filing Code: Cu-550. Producer or source: Copper and copper alloy mills.

Manufacturing Aspects Relating to the Effects of Direct Current on the Tensile Properties of Metals

2007 ◽  
Vol 129 (2) ◽  
pp. 342-347 ◽  
Author(s):  
Carl D. Ross ◽  
David B. Irvin ◽  
John T. Roth
Keyword(s):  
Strain Rate ◽  
Tensile Properties ◽  
Elevated Temperatures ◽  
Cold Work ◽  
Electrical Current ◽  
Deformation Energy ◽  
Strain Behavior ◽  
Metallic Specimen ◽  
Current Flows ◽  
Process Energy

For metals, deformation is commonly conducted at elevated temperatures, reducing the overall process energy and cost. However, elevating the temperature has many drawbacks, including high tool/die adhesions, environmental reactivity, etc. Therefore, this study examines using an electrical current to reduce the deformation energy and presents electricity’s effects on the tensile properties of various materials. The influences of strain rate and cold work are also investigated. The results demonstrate that, when current flows through a metallic specimen, the material’s yield strength, flow stress, and elastic modulus are decreased; strain weakening occurs; and the total energy of deformation is decreased. These changes in the engineering stress-strain behavior occurred in all of the materials tested and are much greater than can be accounted for by resistive heating. However, the effects diminish with increasing strain rate. The analysis shows that applying electricity during deformation provides a viable alternative to increasing the workpiece temperature for deformation-based manufacturing processes.

COPPER ALLOY No. C18090

Alloy Digest ◽  
1992 ◽  
Vol 41 (2) ◽  
Keyword(s):  
Heat Treatment ◽  
Physical Properties ◽  
Tensile Properties ◽  
Copper Alloy ◽  
Cold Work ◽  
Heat Treating

Abstract COPPER ALLOY NO. C18090 is a strip alloy, not hardenable by heat treatment. It may be hardened and strengthened by cold work. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fatigue. It also includes information on forming, heat treating, machining, and joining. Filing Code: Cu-569. Producer or source: Copper and copper alloy mills. See also Alloy Digest Cu-558, March 1991.

Metallo-Thermo-Mechanical Simulation of Carburized Quenching Process by Several Codes - A Benchmark Project -

2007 ◽  
Vol 340-341 ◽  
pp. 1061-1066 ◽  
Author(s):  
Tatsuo Inoue ◽  
Youichi Watanabe ◽  
Kazuo Okamura ◽  
Michiharu Narazaki ◽  
Hayato Shichino ◽  
...  
Keyword(s):  
Experimental Data ◽  
Heat Treatment ◽  
Residual Stresses ◽  
Material Properties ◽  
Helical Gear ◽  
Mechanical Coupling ◽  
Mechanical Simulation ◽  
Quenching Process

As one of the activities carried out by our group of IMS-VHT (Virtual Heat Treatment tool for monitoring and optimising HT process), results of a benchmark project on the simulation of carburized quenching process is summarized. Several programs available for taking into account the metallo-thermo-mechanical coupling had been employed for the simulation for a cylinder, ring as well as a helical gear by use of common data of material properties and cooling characteristics. Comparison of the simulated values of distortion, residual stresses and profile of induced phases with the experimental data is made with some discussions.

CONDULOY

Alloy Digest ◽  
1953 ◽  
Vol 2 (10) ◽  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Physical Properties ◽  
Tensile Properties ◽  
Copper Alloy ◽  
Heat Treating ◽  
Age Hardening ◽  
Beryllium Copper ◽  
Hardening Heat Treatment

Abstract CONDULOY is a low beryllium-copper alloy containing about 1.5% nickel. It responds to age-hardening heat treatment for improved mechanical properties. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on casting, heat treating, machining, and joining. Filing Code: Cu-11. Producer or source: Brush Beryllium Company.

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