Determination of heat treatment parameters for heavily - loaded aircraft engine components

Gears, due to their complex shape, carried load and required accuracy are ones of most complex aircraft engine parts. Single tooth damage usually breaks the power transmission and causes failure of the entire gear system. Adequate sustainability and guarantees of transmission is therefore a condition for secure operation of whole device. Particularly high requirements for reliability are put to transmissions used in the aerospace industry. Due to the loads which are transmitted through the gears, the materials used by the manufacturer must have not only high strength but also show the abrasion resistance of the surface layer and the ductility of the core. Proper parameters matching allows to create an element that can operate at higher stresses and loads. In addition, factor strength and abrasion resistance of the surface layer has a significant impact on the life of the gear. Thermo-chemical treatment of industrial gears is a fundamental process, which gives them adequate mechanical properties regarding loads they carry and the surface conditions of work. Among many methods of thermo-chemical treatment used in the industry, the most distinctive are innovative technologies designed to reduce process costs and being more environmentally friendly. The most promising methods in the discussed field are vacuum carburizing and high-pressure hardening, which by their specification of work significantly reduce the emission of CO2 and the duration of the process, without reducing the quality of the final product. The main aim of the paper is to present criteria for selection of heat treatment parameters as a part of thermo-chemical treatment process performed using vacuum methods. Proper heat treatment parameters are crucial in programming of some of final material characteristics as grain size and retained austenite morphology

Challenges for metals in medicine : how nanotechnology may help to shape the future

Encapsulation of the platinum(IV) prodrug mitaplatin in block copolymer nanoparticles increases drug circulation time in the blood and reduces accumulation in the kidneys, as reported by Lippard and colleagues in this issue of ACS Nano. Importantly, controlled drug release from the nanoparticles produces long-term anticancer efficacy, with the prospect of reduced side effects. We highlight the potential that such a strategy holds for the future development of metallodrugs. Metal coordination complexes offer the prospect of novel mechanisms of activity on account of their unique architectures, as well as potential activation mechanisms, including ligand substitution and metal- and ligand-centered redox properties. Nanoparticles offer exciting prospects for improving delivery, cell uptake, and targeting of metallodrugs, especially anticancer drugs, to make them more effective and safer