Improving the fracture toughness of multi-layered commercial pure aluminum via warm accumulative roll bonding

• In this study, the fracture toughness of the multi-layered commercial pure aluminum samples (AA1050) prepared by warm accumulative roll bonding (WARB) was investigated for the first time. Based on the ASTM E561 standard, the R-curve method was utilized to measure the plane stress fracture toughness. Compact tension (CT) samples were prepared from the sheets that were processed by different ARB cycles. Mechanical properties, microstructure, and fracture surfaces of the CT samples were studied by uniaxial tensile test, electron backscatter diffraction (EBSD), and scanning electron microscopy (SEM), respectively. By increasing the number of WARB cycles, fracture toughness increased; after five cycles, 78% enhancement was observed compared to the pre-processed state. A correlation was seen between the fracture toughness variations and ultimate tensile strength (UTS). WARB enhanced UTS up to 95%, while the grain size showed a reduction from 35 to 1.8 μm. Measured fracture toughness values were compared with the room temperature ARB outcomes, and the effective parameters were analyzed. Fractography results indicated that the presence of tiny cliffs and furrows and hollow under fatigue loading zones and shear ductile rupture in the Quasi-static tensile loading zone.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Materialteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering (hsv//eng)

Keyword

AA1050

Fracture toughness

SEM fractography

Tensile strength

Warm ARB

Aluminum

Aluminum alloys

Computerized tomography

Fracture mechanics

Roll bonding

Scanning electron microscopy

Tensile testing

Accumulative roll bonding

Commercial pure aluminum

Effective parameters

Electron back scatter diffraction

Fracture toughness values

Toughness variations

Ultimate tensile strength

Uniaxial tensile test

Publication and Content Type

ref (subject category)

art (subject category)