Numerical and experimental analysis of heat transfer in inductive conduction based wire metal deposition process

An inductive conduction heating process to heat the extruder in wire additive manufacturing is explored through numerical simulation and an in situ infrared imaging. The 2 D Finite Element Method (FEM) based simulation model provides insights into extruder heating in the inductive conduction heating process. The precise temperature control in the extruder can help achieve the efficient flow of material from extruder. The induction coil design variations to control the extruder temperature are computed numerically to obtain an approximate solution thus offers time and cost-saving. The presented study considers the number of turns of coil, coil radius and coil configurations as the induction coil design parameters whereas coil current, and current frequency are considered to be constant. Based on the results, the design of extruder and geometry of induction coil assembly is proposed to efficiently bring the feed material (Al-5356) to semi-solid state. A thermal imaging method is implemented using an infrared camera to analyse the evolution of thermal fields during extruder heating. Comparison of the extruder tip temperature from simulation and experiments shows an agreeable match with a variation of 8.57%.

Tailored heating of forging billets using induction and conduction heating approaches

Purpose This paper aims to deal with different induction and conduction heating approaches to realize a tailored heating of round billets for hot forming processes. In particular, this work examines the limits in which tailor-made temperature profiles can be achieved in the billet. In this way, a flow stress distribution based on the temperature field in the material can be set in a targeted manner, which is decisive for forming processes. Design/methodology/approach For the heating of round billets by induction, the rotationally symmetric arrangement is used and a parameterized 2D finite element method model is created. The harmonic electromagnetic solution is coupled with the transient thermal solution. For heating by means of conduction, the same procedure is used only with the use of a 3D model. Findings First results have shown that both methods can achieve very good results for billets with small diameters (d < 30 mm). For larger diameters, an adapted control of the heating process is necessary to ensure through heating of the material. Further investigations are carried out. Practical implications Using tailored heating for forging billets, several forming steps can be achieved in one step. Among other things, higher energy efficiency and throughput rates can be achieved. Originality/value The peculiarity of the tailored heating approach is that, in contrast to inhomogeneous heating, where only partial areas are heated, the entire component is heated to the target.

Effect of Microwave or Ultrasound Irradiation in the Extraction from Feather Keratin

The extraction of feather keratin biopolymer structures was studied using chicken feathers as a biomass material by the cold acid hydrolysis reaction; the recrystallization stage was performed using microwave or ultrasound irradiation, and conduction heating was used as a reference. The microwave or ultrasound irradiation modified the texture and the morphology of the obtained materials, and they can be controlled depending on the time exposure and the power of the irradiation; this has high relevance in the design of new materials to obtain nanostructures depending on the specific application. It was found that the microwave irradiation promotes the growth of the beta sheet over the alpha helix, and in the case of ultrasound irradiation, the growth is reversed being similar to the conduction heating; the porosity properties remain invariant, modifying the particle sizes depending on the exposure time and power of irradiation. Therefore, the feather keratin biopolymer, when modified by microwaves and ultrasound in the recrystallization stage, is a fibrous protein that has good mechanical, structural, morphological, and thermal properties with potential applications such as development of biocompatible materials with cellular interaction and in catalysis as catalytic and enzymatic support to mention just a few.