Centre for Mechanical Technology and Automation

Funder

Organizational Unit

Publications

Asymmetrical rolling of aluminum alloys and steels: A review

Publication . Vincze, Gabriela; Simões, Fábio J.P.; Butuc, Marilena C.

Asymmetric rolling is an attractive metal forming process due to its simplicity, low cost and capability to produce unique characteristics in materials. The asymmetry promoted by the process leads to a formation of a large collection of texture components and a refined structure which is capable to improve the mechanical behavior of metallic materials. The aim of this work is to present a perspective of the process and to construct the bases for future development and application of this technique. Thus, several aspects are addressed such as process methods (i.e., dissimilarity of the rolls diameters, rolls angular speed or friction conditions), the process parameters (i.e., total thickness reduction, thickness reduction per pass, peripheral speed ratio, rolling routes) and their effect on material properties, including texture and microstructure evolution, and mechanical properties. This review is focused on the experimental description of asymmetric rolling applied to aluminum alloys and steels. Although the asymmetric rolling application was mostly at a laboratory scale, there is a good perspective for its implementation in the industry. The pros and cons based on the up to date literature and authors’ experience are presented and discussed.

2020Journal article

Open access

Additive manufactured stoneware fired in microwave furnace

Publication . Santos, Tiago; Ramani, Melinda; Devesa, Susana; Batista, Catarina; Franco, Margarida; Duarte, Isabel; Costa, Luís; Ferreira, Nelson; Alves, Nuno; Pascoal-Faria, Paula

Additive manufacturing (AM) techniques have revolutionized the concept of building parts not only in laboratory contexts but also in industry environments and can be applied to distinct fields such as the health, automotive and aeronautics sectors [...]

2022Journal article

Open access

Notch fatigue analysis and crack initiation life estimation of maraging steel fabricated by laser beam powder bed fusion under multiaxial loading

Publication . Branco, R.; Prates, P. A.; Costa, J. D.; Ferreira, J. A. Martins; Capela, C.; Berto, F.

This paper deals with the notch fatigue behaviour and crack initiation life estimation in maraging steel fabricated by laser beam powder bed fusion under multiaxial loading. Tests are conducted in tubular geometries with lateral holes considering different normal stress to shear stress ratios and multiaxial loading levels. The cyclic stress–strain response at the notch-controlled process zone is simulated numerically using two alternative approaches: a generalised isotropic plasticity model with mixed isotropic-kinematic hardening, and a linear-elastic model. Both approaches demonstrated to be suitable for predicting the crack initiation sites, the directions of crack growth, and the fatigue life. Fatigue life was calculated from a SWT-based model combined with the Theory of Critical Distances. Elastic-plastic predictions led to smaller errors but slightly shifted to the non-conservative side.

2021-12Journal article

Restricted access