ADDITIVELY MANUFACTURED LIGHTWEIGHT STEEL STRUCTURES

Abstract

Cellular metallic structures find diverse uses in aerospace, automobile and structural applications as lightweight and protective materials. The advent of additive manufacturing, which enables geometrically complex structures fabricated on the micro-scale, in turn constitutes to the popularity of a class of cellular material known as lattice structures for which has highly tuneable mechanical responses. The current research trends on metallic lattices are nonetheless lacking in specific strength and energy absorption with fundamental limits. In this thesis, new materials, designs and methods are investigated as contributions to better performing metallic lattices as fabricated via selective laser melting. New printable high strength metal-matrix composites and low-alloying steels have been processed. New design methods include finite element modelling, algorithm optimization and interpenetrating phase composites. Structural-property relationships are thoroughly elucidated through experimental and finite element methods. The presented work brings values to metallic lattices researches for its new concepts and deepened structural-property understandings.