Significantly enhanced tensile strength and ductility in nickel aluminium bronze by equal channel angular pressing and subsequent heat treatment

The effects of equal channel angular pressing (ECAP), further heat treatment and rolling on the structure and room temperature mechanical properties of the commercial aluminum alloys 6061 (Al-0.9Mg-0.7Si) and 1560 (Al-6.5Mg-0.6Mn) were investigated. It has been shown that the strength of the alloys after ECAP is higher than that achieved after conventional processing. Prior ECAP solution treatment and post-ECAP ageing can additionally increase the strength of the 6061 alloy. Under optimal ageing conditions a yield strength (YS) of 434 MPa and am ultimate tensile strength (UTS) of 470 MPa were obtained for the alloy. Additional cold rolling leads to a YS and UTS of 475 and 500 MPa with 8% elongation. It was found that the post-ECAP isothermal rolling of the 1560 alloy resulted in the formation of a nano-fibred structure and a tensile strength (YS = 540 MPa and UTS = 635 MPa) that has never previously been observed in commercial non-heat treatable alloys.

Download Full-text

R-Value and Texture Change of AA 1050 Al Alloy Sheet by Equal Channel Angular Pressing

Materials Science Forum ◽

10.4028/www.scientific.net/msf.495-497.803 ◽

2005 ◽

Vol 495-497 ◽

pp. 803-808 ◽

Cited By ~ 6

Author(s):

Saidmurod Akramov ◽

Min Gu Lee ◽

In Soo Kim ◽

Dong Young Sung ◽

Byung Hyun Park ◽

...

Keyword(s):

Heat Treatment ◽

Grain Size ◽

Plastic Strain ◽

Equal Channel Angular Pressing ◽

Subsequent Heat Treatment ◽

Al Alloy ◽

Sheet Metals ◽

Angular Pressing ◽

Fine Grain ◽

R Value

By severe plastic deformation of metals, an ultra fine grain size can be obtained. In the present study an AA 1050 Aluminium alloy has been severe deformed by Equal channel angular pressing (ECAP). A study on the microstructure and the texture of the samples after ECAP and subsequent heat treatment has been carried out. The specimens after ECAP showed a very fine grain size, a decrease of <100> // ND, and an increase of <111> // ND textures. The {111}<112>, {123}<634>, {110}<001>, {112}<111>, {110}<111>, and {013}<231> texture components were increased in the specimens after the ECAP and subsequent heat-treatment at 400° C for 1 hour. One of the most important properties in sheet metals is formability. The r-value or plastic strain ratio has been used as a parameter that expresses the formability of sheet metals. The change of the plastic strain ratios after the ECAP and subsequent heat-treatment conditions has been investigated and it was found that they were two times higher than those of the initial Al sheets. This could be attributed to the formation above texture components through the ECAP and subsequent heat-treatment.

Download Full-text

Improving the Strength and Ductility of Magnesium Alloys by Grain Refinement and Texture Modification

Materials Science Forum ◽

10.4028/www.scientific.net/msf.488-489.177 ◽

2005 ◽

Vol 488-489 ◽

pp. 177-180

Author(s):

T. Liu ◽

Yan Dong Wang ◽

Shi Ding Wu ◽

Shou Xin Li ◽

Ru Lin Peng ◽

...

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Grain Refinement ◽

Magnesium Alloys ◽

Equal Channel Angular Pressing ◽

Room Temperature ◽

Angular Pressing ◽

Texture Modification ◽

Strength And Ductility

The room temperature tensile strength and ductility of Mg-3.3%Li alloy were improved simultaneously by two kinds of different equal channel angular pressing (ECAP) treatments. Microstructural analyses showed that grain refinement and texture modification are the principal reasons for the improvement of mechanical properties.

Download Full-text

Sheet Formability of AA 1050 Al Alloy Sheet by Equal Channel Angular Pressing of Route C Type

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.116-117.324 ◽

2006 ◽

Vol 116-117 ◽

pp. 324-327 ◽

Cited By ~ 3

Author(s):

Saidmurod Akramov ◽

In Soo Kim ◽

Min Gu Lee ◽

Byung Hyun Park

Keyword(s):

Heat Treatment ◽

Equal Channel Angular Pressing ◽

Strain Ratio ◽

Alloy Sheet ◽

Heat Treatment Condition ◽

Subsequent Heat Treatment ◽

Al Alloy ◽

Plastic Strain Ratio ◽

Angular Pressing ◽

Sheet Formability

Ultra-fine grained and high hardened Al sheet was obtained by Equal Channel Angular Pressing (ECAP). During this process the microstructure, the hardness and the texture of AA 1050 Al alloy sheet are changed by a severe shear deformation. The plastic strain ratio after the ECAP and subsequent heat-treatment condition was investigated in this study. It was found that the average r-value of the equal channel angular pressed and subsequent heat-treated specimen was 1.7 times higher than that of the initial Al sheet. This could be attributed to the various texture formations through the ECAP and subsequent heat-treatment of AA 1050 Aluminum alloy sheets.

Download Full-text

ECAP Processed Copper during Deformation and Subsequent Annealing

Materials Science Forum ◽

10.4028/www.scientific.net/msf.503-504.469 ◽

2006 ◽

Vol 503-504 ◽

pp. 469-474 ◽

Cited By ~ 9

Author(s):

Xenia Molodova ◽

Sheila Bhaumik ◽

Myrjam Winning ◽

Günter Gottstein

Keyword(s):

Heat Treatment ◽

Texture Analysis ◽

Equal Channel Angular Pressing ◽

Crystallographic Texture ◽

Texture Evolution ◽

Pure Copper ◽

Equivalent Strain ◽

Subsequent Heat Treatment ◽

Angular Pressing ◽

Different Temperatures

Microstructure and texture evolution of pure copper (99.95%) after Equal-Channel Angular Pressing (ECAP) and subsequent heat treatment were investigated. Initially the material was subjected up to twelve passes with a 90° die angle using route Bc. This resulted in an equivalent strain of 13.8. After deformation the samples were annealed at different temperatures. The deformed and annealed states were characterized by using the crystallographic texture analysis, EBSD measurements and microhardness tests.

Download Full-text