Precipitation mechanisms and subsequent hardening kinetics in the β-CEZ alloy

The β-CEZ alloy : Ti-5%Al-2%Sn-4%Zr-4%Mo-2%Cr-l%Fe is a near β titanium alloy. Since its processing routes include heat treatment (consisting of solution treatment and ageing), it has been decided to study the influence of the β phase stability on α phase precipitation and hardening kinetics. Small sized specimens, coming from industrial heats, have been heat treated above and below the β transus, and then water quenched. Therefore, several degree of β stability are obtained. When it is increased (i.e. the solution treatment temperature is lowered), α or ω phases precipitations are delayed, as well as the hardening phenomena. Moreover, the ω stability domain is reduced. The mechanisms of α or ω precipitation are discussed, and related to the hardening kinetics

Irrigere : a generalized version of an irrigation scheduling model for a wide range of crops

International audienc

The effect of the elemental composition of municipal sewage sludge on the phosphorus recycling during pyrolysis, with a focus on the char chemistry:modeling and experiments

Abstract The present study investigates how the original sewage sludge characteristics influence the composition of sewage sludge-based chars for land applications. Sewage sludge from two different wastewater treatment plants in Sweden was pyrolyzed at 500, 700, and 900 °C, and the resulting chars were analyzed. Thermodynamic equilibrium calculations (TEC), together with chemical fractionation, were implemented to simulate the char after the pyrolysis process at different temperatures. The results showed that, in general, for both the municipal sewage sludge (MSS), phosphorus (P) was significantly retained in the char at various temperatures. However, no specific correlation could be found between the pyrolysis temperature and the amount of P remaining. With regard to the heavy metals removed from the char after the pyrolysis reaction, the concentrations of copper, chromium, lead, nickel, zinc, and cadmium were below the limits of the Swedish regulations for farmland application

Precipitation mechanisms and subsequent hardening kinetics in the #beta#-CEZ alloy

Published in the Proceedings of 'Congres EUROMAT 93', Paris (France), June 8-10, 1993SIGLEAvailable at INIST (FR), Document Supply Service, under shelf-number : 22419, issue : a.1993 n.117 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc