Fractal dimension of fracture surface and superplasticity of 7475 Al alloy

The fatigue life of 7050 Al alloy samples after different surface treatments, i.e., as-machined, anodizing, shot peening, and shot peening followed by anodizing, had been tested. The shot peening treatment specimens presented the longest average fatigue life. The fatigue life of anodizing treatment specimens decreased by 69.3% and 78.8% at 215 MPa and 260 MPa stress levels than as-machined ones. Introducing the shot peening treatment before anodizing can increase the fatigue life by 220% / 296.9% at 215 MPa/260 Mpa than that only treated by anodizing. The effect of the surface treatments on the fatigue life were studied by performing surface morphology investigation, residual stress measurements and fracture surface analysis.

Download Full-text

Fractal dimension studies of porous ZrO2-MgO fracture surface

10.1063/1.5131912 ◽

2019 ◽

Cited By ~ 1

Author(s):

A. S. Buyakov ◽

S. N. Kulkov

Keyword(s):

Fractal Dimension ◽

Fracture Surface

Download Full-text

Fracture Surface Fractal Characteristics of Alkali-Slag Concrete under Freeze-Thaw Cycles

Advances in Materials Science and Engineering ◽

10.1155/2017/1689893 ◽

2017 ◽

Vol 2017 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Wantong Cai ◽

Guoping Cen ◽

Haifu Wang

Keyword(s):

Fracture Toughness ◽

Fractal Dimension ◽

Fracture Surface ◽

Fractal Theory ◽

Damage Zone ◽

Freezing And Thawing ◽

Freeze Thaw ◽

Force Direction ◽

Fractal Characteristics ◽

Slag Content

Fractal theory is introduced in fracture surface research of alkali-slag concrete (ASC) under freeze-thaw cycles; crack distribution of ASC fracture surface and freeze-thaw damage zone were calculated. Through fractal analysis of ASC sample fracture surfaces, relevance between section fractal dimension and fracture toughness and relationship between material composition and section fractal dimension are clarified. Results show that the specimen’s cracks before freeze-thaw extend along force direction gently, and there are more twists and turns after freezing and thawing; the fractal dimension D also grows from 1.10 to 1.33. SEM internal microcracks’ D of ASC internal microstructure after freezing and thawing is 1.37; 0 to 300 times ASC fractal dimension under freezing and thawing is between 2.10 and 2.23; with freeze-thaw times increasing, ASC fracture toughness decreases and fractal dimension increases, the fractal dimension and fracture toughness have a good linear relationship, and the fractal dimension can reflect the toughening effect of ASC. It is very feasible to evaluate ASC fracture behaviour under freezing and thawing with the fractal theory. Fractal dimension generally increases with activator solution-slag (A/S for short) or slag content. The greater the amount of A/S or slag content, the lower the dimension.

Download Full-text