In-Depth Understanding of Granule Compression Behavior under Variable Raw Material and Processing Conditions

Tablet manufacturing involves the processing of raw materials through several unit operations. Thus, the mitigation of input-induced variability should also consider the downstream processability of intermediary products. The objective of the present work was to study the effect of variable raw materials and processing conditions on the compression properties of granules containing two active pharmaceutical ingredients (APIs) and microcrystalline cellulose. Differences in compressibility and tabletability of granules were highlighted in function of the initial particle size of the first API, granule polydispersity and fragmentation. Moreover, interactions were underlined with the atomizing pressure. Changing the supplier of the second API was efficiently controlled by adapting the binder addition rate and atomizing pressure during granulation, considering the starting crystal size. By fitting mathematical models on the available compression data, the influence of diluent source on granule compactibility and tabletability was identified. These differences resumed to the ease of compaction, tableting capacity and pressure sensitivity index due to variable water binding capacity of microcrystalline cellulose. Building the design space enabled the identification of suitable API types and the appropriate processing conditions (spray rate, atomizing pressure, compression force) required to ensure the desired tableting performance.

Effect of Extrusion Temperature and Feed Moisture Content on the Microstructural Properties of Rice-Flour Pellets and Their Impact on the Expanded Product

Extrusion can lead to an expanded product or to a slightly expanded pellet, known as a third-generation (3G) snack. In this case, expansion occurs subsequently, in an independent thermal device (e.g., oven), out of the extruded pellet. During both processes, several structural changes occur which are linked to processing conditions, including cooking temperature, screw speed, formulation, and initial moisture content. However, a clear relationship between processing variables and the structure of pellets and expanded products has not yet been identified. Accordingly, this work aimed to study the effect of extrusion temperature (110, 135, and 150 °C) and moisture content (27, 29, and 31%) in rice-flour pellets and their microwave expansion, through a microstructural approach using micro-CT. The results showed that the lowest moisture content (27%) and the highest extrusion temperature (150 °C) led to the highest pellet volume and the highest wall thickness, which in turn led to the highest expansion after microwave heating (50 s, 800 W). Interestingly, no significant differences were observed when analyzing the ratio between the volume of the expanded products and the volume of the pellet (~2.4) when using the different processing conditions.

Ultrasonic additive manufacturing of nanocrystalline laminated composites

Ultrasonic additive manufacturing has been used to fabricate laminated composites of commercially pure aluminum and a nanocrystalline nickel–cobalt (nc-NiCo) alloy. The nc-NiCo alloy would not weld to itself but readily welded to aluminum. Thus, by alternating between foils of nc-NiCo and Al, we achieved multi-material laminates with strong interlayer bonding. Electron microscopy showed that the nanoscale grain structure of the nc-NiCo was preserved during deposition and that the nc-NiCo/Al weld interface was decorated with comminuted surface oxides as well as Al–Ni–Co intermetallics. These findings are considered in light of process models of junction growth, interdiffusion, and grain growth, which together reveal how the different pressure- and temperature dependences of these phenomena give rise to a range of processing conditions that maximize bonding while minimizing coarsening and intermetallic formation. This analysis quantitatively demonstrates that using a soft, low melting point interlayer material decouples junction growth at the weld interface from grain growth in the nc-NiCo, expanding the range of optimal processing conditions. Graphical abstract

A Compendium of Deformation-Mechanism Maps for Metals

Deformation-mechanism maps represent an invaluable guide to predicting the optimum processing conditions for a material. They are also useful in matching a material to a given engineering application. The present book summarizes recent research results in the field. The book references 106 original resources and includes their direct web link for in-depth reading.

Nitinol Type Alloys General Characteristics and Applications in Endodontics

A very extensive literature review presents the possibilities and needs of using, in endodontics, the alloys commonly known as nitinol. Nitinol, as the most modern group of engineering materials used to develop root canals, is equilibrium nickel and titanium alloys in terms of the elements’ atomic concentration, or very similar. The main audience of this paper is engineers, tool designers and manufacturers, PhD students, and students of materials and manufacturing engineering but this article can also certainly be used by dentists. The paper aims to present a full material science characterization of the structure and properties of nitinol alloys and to discuss all structural phenomena that determine the performance properties of these alloys, including those applied to manufacture the endodontic tools. The paper presents the selection of these alloys’ chemical composition and processing conditions and their importance in the endodontic treatment of teeth. The results of laboratory studies on the analysis of changes during the sterilization of endodontic instruments made of nitinol alloys are also included. The summary of all the literature analyses is an SWOT analysis of strengths, weaknesses, opportunities, and threats, and is a forecast of the development strategy of this material in a specific application such as endodontics.