Instituto Tecnológico de Saltillo

About: Instituto Tecnológico de Saltillo is a education organization based out in Saltillo, Mexico. It is known for research contribution in the topics: Microstructure & Alloy. The organization has 229 authors who have published 247 publications receiving 3178 citations.

Mechanism and kinetics of strain induced precipitation of Nb(C,N) in austenite

Abstract: A model for strain induced precipitation of Nb(C,N) nucleating on all nodes in the dislocation network is shown to give reasonable agreement with observed particle densities and strengthening at about 5% of equilibrium precipitation. Subsequent growth controlled by volume diffusion, with concurrent coarsening by accelerated pipe diffusion along the dislocation links, accounts for the observed rapid decrease in number of particles per unit volume as precipitation proceeds, with loss of the precipitation strengthening. By pinning the dislocation nodes, particles initially prevent recovery taking place and hence prevent the formation of recrystallisation nuclei. Particle coarsening relaxes these constraints. Multipass finishing, leading to reduced coarsening and repeated nucleation of new particles enhances the precipitation strengthening and the retardation of recrystallisation. The proposed model provides a physical basis for interpreting the influence of the thermochemical variables in industrial finish rolling.

Electrochemical Reactions for Electrocoagulation Using Iron Electrodes

Abstract: Electrocoagulation (EC) has been known for more than a century. Applications in industries such as water and wastewater treatment processes have been adapted for the removal of metals, nonmetals, suspended solids, organic compounds, COD (chemical oxygen demand), and BOD (biological oxygen demand). Iron electrodes have been preferred over aluminum due to their durability and cost. However, the electrochemical reactions occurring with EC using iron electrodes have not been systematically studied. For a better understanding of the mechanism and reactions for EC using iron electrodes, we present a review of the concept of green rust (GR) and its relationship to the current theory of EC. Experimental results obtained by measuring pH at different zones near the iron electrodes during the EC process are detailed, and are used to illustrate the mechanism and reactions that occur at both the anode and the cathode. The mechanism and reactions presented explain phenomena associated with EC and are congruent with sol...

Transactions of the Indian Institute of Metals

Abstract: Transactions of The Indian Institute of Metals is devoted to the publication of selected reviews on contemporary topics and original research articles that contribute to the advancement of ferrous and non-ferrous process metallurgy, materials engineering, physical, chemical and mechanical metallurgy, welding science and technology, surface engineering and characterisation, materials development, thermodynamics and kinetics, materials modelling and to other allied branches of metallurgy and materials engineering.

Temperature effects on the tensile properties of cast and heat treated aluminum alloy A319

Abstract: In this work, the tensile properties and ductility of an Al-A319 alloy were investigated as a function of temperature and heat treatment. Tensile testing was carried out at temperatures ranging from −90 to 400 °C for the alloy in (a) the as-cast condition, (b) after solid solution at 485 °C (T4) and (c) after solid solution followed by ageing at 230 °C (T7). It was found that the alloy tensile strength was improved by heat treating from 195 MPa in the as-cast condition to 305 MPa in the T7 condition. Nevertheless, the alloy elongation was relatively poor, in the 2–3% all the way to temperatures in the neighborhood of 300 °C. The low alloy ductility was found to be related to internal damage dominated by cracking of intermetallic α-Al 15 (Mn,Fe) 3 Si 2 and θ-Al 2 Cu particles including silicon. Heat treating was found to increase the work hardening exponent, n in the σ = Kɛ n expression from 0.23 to almost 0.29. Moreover, it was found that n was not severely affected by temperature for temperatures below 200 °C. However, temperatures beyond 200 °C lead to appreciable reductions and overlapping in the magnitudes of n when compared with the as-cast condition. In turn, this indicated that above 200 °C, the work hardening properties of alloy A319 imparted by heat treating tend to dissipate. Apparently, bulk precipitate coarsening coupled with alloy softening mechanisms become active and they are dominant at temperatures above 300 °C. Moreover, the fraction of cracked particles was found to increase with temperature in this temperature regime. Weibull statistics and the probability of particle cracking indicated that at temperatures below 300 °C, damage accumulation by particle cracking is the dominant mode of fracture as indicated by the slope, m = 3 of the linear Weibull plot. Depending on the alloy condition, critical particle stresses for cracking of 0.5–3 GPa were predicted using Weibull statistics.