Describing crack growth in additively manufactured Scalmalloy

Fatigue crack growth behavior in an aluminum alloy Al–Mg–0.3Sc produced by wire based directed energy deposition process

“…This means that only one test is needed to determine the cyclic fracture toughness A and threshold stress intensity factor K th under just one load ratio, which can then be used for other load ratios within 0.1 and 0.5. This finding agrees with the work by Jones et al on a study of L‐PBF Al–Mg–Sc–Zr alloys 56 …”

“…takes the load ratio effect into account in terms of the maximum stress intensity factor K max ; it describes the entire range of crack growth rate data by two governing parameters, Δ K and K max (where ∆K = [1‐ R ] K max ) and two additional material constants, ∆K th and A . It was validated by testing several materials, 32,33,55 including an additively manufactured aluminum alloy with Scandium content, the Scalmalloy 56 . It has been proven to represent well the crack growth rates of various alloys, including aluminum alloys for aerospace applications 33 .…”

“…It was validated by testing several materials, 32,33,55 including an additively manufactured aluminum alloy with Scandium content, the Scalmalloy. 56 It has been proven to represent well the crack growth rates of various alloys, including aluminum alloys for aerospace applications. 33 Therefore, it was selected for the current study.…”

“…This finding agrees with the work by Jones et al on a study of L-PBF Al-Mg-Sc-Zr alloys. 56 Finally, the experimental data is plotted in terms of da/dN versus applied ΔK in Figure 7, with an upper bound curve generated by the modified H-S eq. (Equation (3)) using average values for D and p. The upper bound curve can serve as the worst crack growth rate property value for damage tolerance design and assessment.…”

A Numerical Study into the Effect of Machining on the Interaction between Surface Roughness and Surface Breaking Defects on the Durability of WAAM Ti-6Al-4V Parts

“…A feature of this formulation is that, as noted in [47], for AM Ti-6Al-4V, when allowance is made for the effect of the different build processes and post built processing on the terms ∆K thr and A, then each of the da/dN versus ∆κ curves in the 30 different tests analysed in [48], the 34 different tests in [49], and the 13 different tests in [50] all collapse onto the same master curve. As such, for both conventionally and AM Ti-6Al-4V the values of D (=2.79 × 10 −10 ) and p (=2.12) are true materials constants, and remain the same for each of these seventy seven tests.…”