Fractography

About: Fractography is a research topic. Over the lifetime, 5043 publications have been published within this topic receiving 86068 citations.

Fractography of glass

Abstract: Identation Fractography (B.R. Lawn, D.B. Marshall). Quantitative Fractographic Analysis of Fracture Origins in Glass (J.J. Mecholsky). Stress Wave Fractography (H. Richter, F. Kerkhof). Fractography of Stress Corrosion Cracking in Glass (T.A. Michalske). Fractography of Optical Fibers (H.C. Chandan et al.). Fractography of Fiberglass (P.K. Gupta). Fracture of Glass Containers (J.B. Kepple, J.S. Wasylyk). Fracture and Fractography of Flat Glass (N. Shinkai). Index.

Split Hopkinson pressure bar tests for investigating dynamic properties of additively manufactured AlSi10Mg alloy by selective laser melting

Abstract: Dynamic properties of additively manufactured AlSi10Mg alloy by selective laser melting (AM–SLM-processed) have been investigated using the split Hopkinson pressure bar (SHPB) system. Additive manufacturing (AM) processes have attracted increased attention over the past three decades, and AlSi10Mg is an alloy commonly used in AM processes. AlSi10Mg is a widely used material, and has been a subject of extensive investigations concerning its microstructure, quasi-static properties, and post-processing. Nonetheless, dynamic mechanical properties of this alloy are yet to be explored over a wide range of strain rates. Dynamic properties of X- and Z-oriented AlSi10Mg alloy samples in the as-built and T5 heat-treated (T5-HT) states were investigated using SHPB under strain rates varying over a range of 700–7900 s−1. The investigation revealed an important dependence of dynamic properties of the said alloy on build orientation when subjected to strain rates range of the order of 1000–3000 s−1. At values of strain rate above and below this range, the observed dependency no longer existed. In addition, dependency of dynamic properties of the alloy on its thermal state (as-built versus T5-HT state) was investigated for the first time along with detection of no-strain-rate sensitivity of the AM-SLM-processed AlSi10Mg alloy. A pronounced ellipticity was observed in most samples, thereby reflecting the anisotropic nature of the alloy. Fractography and optical microscopy analyses revealed differences between fracture morphologies observed in the as-built and T5-HT samples. Cracks observed were predominantly of the radial type (with minor circumferential cracks) under the brittle fracture mode in as-built samples. In contrast, T5-HT samples mainly demonstrated the ductile mode of deformation.

The influence of tensile stress states on the failure of HY-100 steel

Abstract: The failure of an HY-100 steel plate has been examined as a function of stress state using notched and un-notched axisymmetric tensile specimens. The results show that increasing stress triaxiality leads to a rapid decrease in failure strains in a manner that is exponentially dependent on the degree of triaxiality. Two ductile failure mechanisms are identified: a void coalescence process, in which relatively equiaxed voids grow to impingement, and a void-sheet process, which links by a shear instability process large, elongated inclusion-initiated voids. The void-sheet mechanism intervenes and limits ductility at high-stress triaxialities in transversely oriented HY steel plate material, whereas the former process controls failure in longitudinally oriented material. These orientation effects are related to the morphology and alignment of the nonmetallic inclusion stringers that act as the primary void nucleation sites. Calcium treatments for inclusion-shape control improve ductility, especially at intermediate-stress triaxialities, primarily by suppressing the local conditions which give rise to the void-sheet instability process.