Additive manufacturing is now a fast-growing technology with its applications in a variety of areas such as biomedical implants, aerospace components and structures. Achieving complex-shaped architectures in high melting temperature alloys and in ceramics is, however, still challenging. This session will focus on solving the problem of applying nanostructured ceramic materials with complex shapes, and the new concepts of supra-nanostructured materials and nanostructured dual phase (glass-nanocrystal) composites will be discussed. 4D printing enables more complex shapes to be created than is possible with conventional 3D printing. Achieving this in ceramics, however, has been hindered by the fact that 3D-printed ceramic precursors are usually rigid and thus difficult to be deformed after fully crosslinked. The directly 3D printed metallic materials has lower fatigue resistance compared to its counterparts produced by the powder metallurgy technologies including HIP. We will present their potential application in biomedical implants. The post treatment of 3D printed components in Ti alloy can drastically enhance the fatigue resistance. Finally, the perspective of new 4D printing methods with associate control media will be presented. 

For more details, follow this link.

Lecture 2

Early Stages of Crack Development in Environmentally Assisted Cracking
Dr Alan Turnbull, NPL
Tuesday, February 16, 2021 (10:00 GMT)

The overall life of a component of structure that may fail by environmentally assisted cracking is commonly determined by a number of steps: precursor development; transition to a crack; small crack growth; long crack growth. The prior surface state and surface preparation method can be critical; for example, machining and grinding can introduce surface defects, residual stress, and nanocrystalline and heavily deformed surface layers, all of which may impact on precursor and early crack development.

The nature of the crack precursor will depend on the alloy and the loading and exposure conditions. Examples include dealloyed layers, corrosion pits, physical defects (especially at welds), grain boundary oxides, but for this presentation the focus will be restrained to dealloyed layers and to corrosion pits.

For more details, follow this link.

Lecture 3

Regenerating Structural Integrity Using Degradable Biomaterials
Professor Serena Best, University of Cambridge
Tuesday, June 29, 2021* (10:00 GMT)
*Moved from March 23, 2021

The development of biomedical materials to replace human tissues damaged by injury or disease has been of interest for thousands of years. However, over time, the materials of choice have gradually changed from those that simply offer mechanical support to those that interact directly with the biological environment. Focus now ranges from the recruitment and delivery of biological cells to assist in the tissue regeneration to the support and repair of tissues. With a move from tissue replacement to cell-mediated tissue reconstruction and regeneration, there is increasing need for the design of appropriate biomaterial “scaffolds” and there has been a focus on materials that will assist in the tissue regeneration, but which will then be removed naturally from the body—avoiding the risks associated with a second surgery. Three examples will be considered, covering a range of applications including: calcium phosphates for bone grafting, collagen scaffolds for cell delivery and poly alpha acids for bone-repair and vascular applications. To optimise the tissue response using these scaffolds, it is important to understand the influences on cell behaviour of structure and chemistry, and the balance required between “activity”, degradation and mechanical performance. This talk will cover recent work undertaken to study the structure and properties of scaffolds for a range of clinical applications in soft- and hard-tissue repair.

For more details, follow this link.

Lecture 4

Materials and Structural Integrity Challenges for Offshore Wind Energy Systems
Professor Feargal Brennan, University of Strathclyde and Dr Ali Mehmanparast, Cranfield University
Tuesday, April 27, 2021 (10:00 GMT)

Offshore wind is an efficient source of renewable energy and is increasingly the preferred solution for realising Britain’s short- and long-term energy ambitions. While Britain is presently the global leader in offshore wind energy, the national target set by the UK government to increase the currently installed offshore wind capacity from approximately 10 GW in 2020 to 40 GW in 2030 demonstrates the strategic importance of this clean source of energy in the UK’s energy mix. The rapid expansion of the offshore wind capacity will not only escalate UK’s position in this emerging market, but will also significantly contribute to the UK’s world-leading net-zero greenhouse gas emissions target by 2050. Offshore wind turbines (OWTs) are typically designed for 20–25 years of operation. One of the main challenges in the design and life assessment of OWTs is the evolution of corrosion-fatigue damage due to the constant exertion of wind, wave and current forces in the highly corrosive environments. The aim of this talk is to present the materials and structural integrity challenges associated with the currently installed and future generation of OWTs, with the view to maximise the operational life, reduce the number of frequent inspections and deliver a direct beneficial impact on Operations and Maintenance (O&M) costs.

For more details, follow this link.

Lecture 4

On the Fracture Toughness of Biological and Engineering Structural Materials
Dr Robert O Ritchie, University of California
Tuesday, May 18, 2021 (15:00 GMT)

A material’s capacity for limited deformation is a critical aspect of toughness as this enables the local dissipation of stresses that would otherwise cause fracture. Such inelastic deformation mechanisms are diverse; they include dislocation motion in crystalline materials, in-situ phase-transformations in certain metals and ceramics, sliding of collagen fibrils in bone, the rotation of fibrils in skin, frictional motion between mineral “platelets” in seashells, and through mechanisms that also cause fracture such as shear-banding in glasses and microcracking in rocks. Resistance to fracture is thus a compromise: either a combination of the mutually exclusive properties of strength and deformability, as in intrinsic toughness, or between intrinsic and extrinsic (shielding) mechanisms that act to induce toughness, respectively, ahead or behind, the tip. We examine the interplay between such mechanisms in biological materials, including skin and bone, seashells and fish scales, in high-temperature materials, such as ceramic-matrix composites and nuclear graphite, and in multiple-element metallic alloys, namely bulk-metallic glasses and high-entropy alloys, in order to seek the many diverse processes that are the source of the fracture resistance of materials.

For more details, follow this link.