ABSTRACT
Estimation of flow stress of the work material is central to both analytical and numerical modelling of the machining process. Results from split Hopkinson's pressure bar (SHPB) testing were used as a starting point for the estimation of flow stress. Subsequently material flow stress valid in the context of chip formation was computed from analytical model based on results from orthogonal milling tests. The milling operation involving cyclic variation of thickness of cut was carried out for a range of cutting speeds, generating information about flow stress over a wide range of strain, strain rate, and temperatures. Two work materials differing in phase content, namely pure ferritic (REMKO) and pure austenitic (AISI 316L) were the reference materials evaluated in this study.
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Notes
1Parameters obtained with continuous chip model for strain and strain rate.
2Parameters obtained with chip serration model for strain and strain rate.
1Parameters obtained from orthogonal milling tests with continuous chip model for strain and strain rate.
2Parameters obtained from orthogonal milling tests with serrated chip model for strain and strain rate.
3Parameters obtained from Hopkinson's test on “hat” shaped specimen at room temperature.
4M'Saoubi (Citation[9]): parameters obtained from Hopkinson's test on cylindrical specimen at T° up to 300°C.
5Changeux (Citation[10]): parameters obtained from Hopkinson's test on “hat” shape specimen at T° up to 300°C.
6Tounsi et al. (Citation[3]) parameters obtained from machining tests (turning AISI316 at 250HB).
τexp – flow stress based on experimentally measured cutting forces.
τnum – (1) to (6) – correspond to calculated flow stress values obtained using the 6 variants of material constants from the present study and literature information shown in Table 4.