Electrothermography apparatus for kinetics of rapid high-temperature reactions

Abstract

A computer-assisted electrothermography setup has been developed to determine the intrinsic kinetics of rapid heterogeneous reactions under conditions of high heating rate. In this method, metal wires are heated in a reactive gas atmosphere to desired temperature in a controlled manner by passing electric current, and then by measuring time-dependence characteristics of electric power applied to the wire, the reaction kinetics is extracted. The described setup allows heating rates up to 3×105 K/s and permits investigation of reaction kinetics over time scale of few milliseconds to seconds. Other applications are also possible that require fast heating and temperature control.

Microstructural transformations and kinetics of high-temperature heterogeneous gasless reactions by high-speed x-ray phase-contrast imaging

“…After this time, the power input to the wire is equal to the heat losses and the temperature remains constant. 26,27 …”

“…26,27 In brief, a composite wire is placed between terminal blocks in the reaction chamber and is heated by passing electric current using a high-speed temperature controller. The temporal temperature profile for the wire can be preset and the computer program adjusts the input current as required to match the profile through a high-speed optical temperature sensor and feedback loop.…”

Influence of preheating rate on kinetics of high‐temperature gas–solid reactions

“…We have developed a computer-assisted electrothermography method (CAE) to determine the intrinsic kinetics of re-Correyzmndencc concerning this iirliclr should hc addre\scd 10 A. Varma. actions under conditions similar to those realized during CS (Pelekh et al, 2000). Some preliminary results obtained €or the interaction in the titanium-nitrogen system show that the reaction rate depends on the preheating rate of the reaction system (Pelekh et al, 1999).…”

“…A CAE setup (see Figure 11, designed and built in our laboratory specifically to investigate the influence of preheating rate on the reaction behavior, is described elsewhere (Pelekh et al, 2000). Briefly, for gas-solid systems, a metal wire (such as Nb or Ti) is placed in a reaction chamber under a steady flow of gaseous reactant (such as nitrogen).…”

Kinetics of Heterogeneous Self-Propagating High-Temperature Reactions

“…Because of this, a number of experiments were conducted in nitrogen environments. In specific, the Ta/N [94], Ti/N [95][96][97][98], Nb/N [98,99], and Zr/N [8] systems have been studies. However, the technique has also be used to study carbides, including the Ti/C [100], Zr/C [100], W/C [101], Nb/C [102], along with other systems, including Mo/ Si [103][104][105][106], W/Si [107,108], Ni/Al [109], and Ni/Ti [109].…”