Quantitative fractographic analysis of variability in the tensile ductility of high-pressure die-cast AE44 Mg-alloy

Prediction of tensile variability by simulations of microstructures having controlled variations of porosity in Mg-alloy pressure die-castings

“…It has already been reported [3,4,9] that the amount of porosity present in the fracture surfaces of the tensile test specimens was significantly higher than the average volume fraction of porosity in the bulk microstructures. Therefore, it is reasonable to think that the fracture path preferentially go through the regions of the specimens that contain large amounts of localized porosity, which is supported by the quantitative correlation between the tensile ductility and the area fraction of the porosity in the fracture surfaces [3,4,9]. The area fraction of the porosity at the fracture surfaces can be simply estimated by the stereological principles, L L P =A A P , where L L P is the projected length of the porosity at the fracture surface, and A A P is the projected area of the porosity at the fracture surface.…”

“…In particular, in recent years [1,2], cast magnesium alloys have received considerable attention for being used as structural applications due to their high strength to weight ratio. It is well known [3,4] that, if several pieces of the same component were cast by using the same process, and same average alloy chemistry, they may not necessarily have the same values of fracture sensitive properties, despite having the same average microstructure. For example, tensile test specimens machined from the same region of such castings may not have the same ductility and strength (or fatigue life), and therefore, a distribution of ductility (or strength, or fatigue life) values is usually present in the cast alloys.…”

Effects of Stress Triaxiality on Damage Evolution from Pre-Existing Hydrogen Pores in Aluminum Alloy

“…The thermo-mechanical treatments were also identical to those in the previous study. 16) Total hydrogen content, which is expressed as the equivalent volume of hydrogen gas at 0°C and 1 atm per 100 g of aluminum, was 0.48 cm 3 per 100 g of Al. I-shaped specimens (0.6 (Width: W) © 0.6 (Thickness: B) © 11 (Length: L) mm) were sampled in the LT orientation using an electro-discharge machine.…”

Effect of Hydrostatic Pressure on the 3D Porosity Distribution and Mechanical Behavior of a High Pressure Die Cast Mg AZ91 Alloy

“…A large number of studies have tried to relate HPDC microstructures to their mechanical behavior. [10][11][12][13][14][15][16][17][18][19][20][21][22] In general, it is agreed that porosity is the microstructural feature that has the most deleterious effect on the mechanical properties. In particular, the presence of pores gives rise to fracture at smaller strains than in their wrought counterparts.…”

“…[17] It has been proposed that tensile ductility is not related to the bulk volume fraction of pores, but to the area fraction of the pores at the fracture surface. [13][14][15][16]20,21] Several studies have aimed at modeling the correlation between ductility and porosity. [10][11][12]22] Some have attempted to include 3D information of the porosity distribution into models of cast alloys.…”