Electrically Assisted Manufacturing

Journal of Manufacturing Science and Engineering

2011

Recent development of electrically-assisted manufacturing (EAM) processes proved the advantages of using the electric current, mainly related with the decrease in the mechanical forming load and improvement in the formability. Erom EAM e.xperiments, it has been determined that a portion of the applied electrical power contributes toward these forming benefits and the rest is dissipated into heat, defined as the electroplastic effect. The objective of this work is to experimentally investigate several factors that affect the electroplastic effect and the efficiency of the applied electricity. Specifically, the effects of various levels of cold work and contact force are explored on both Grade 2 and Grade 5 Titanium alloys. Thermal and mechanical data prove that these factors notably affect the efficiency of the applied electricity during an electrically-assisted forming (EAF) process.

Section: Development Of Eammentioning

confidence: 99%

Several Factors Affecting the Electroplastic Effect During an Electrically-Assisted Forming Process

Salandro

Bunget

Journal of Manufacturing Science and Engineering

2011

“…Additional work by Kronenberger material flow stress during EAF; however, using only the resistive heating effects, the model was inadequate at predicting the EAF flow stress [6]. Also in 2010, Salandro et al examined air bending of 304 Stainless Steel sheet metal [8]. This work presented a model which accurately characterized the material flow stress for small and larger strains in magnesium and copper materials.…”

Section: Flow Stress Prediction In Electrically Assisted Formingmentioning

confidence: 99%

“…This work presented a model which accurately characterized the material flow stress for small and larger strains in magnesium and copper materials. In 2011, Salandro et al performed thermal modeling of a uniaxial EAF compression process to study the effects of electrical energy input and its contribution to resistive heating or to aiding deformation [10]. Using an analytical approach, a model of the forming load was constructed for conventional bending and electrically assisted bending.…”

Section: Flow Stress Prediction In Electrically Assisted Formingmentioning

confidence: 99%

Alternative Control of an Electrically Assisted Tensile Forming Process Using Current Modulation

Jones¹,

Journal of Manufacturing Science and Engineering

2013

Electrically assisted forming is a technique whereby metal is deformed while simultaneously undergoing electric current flow. Using this process, electric current level becomes a new degree of freedom for process control. In this work, we present some alternative control architectures allowing for new avenues of control using such a process. The primary flndings are architectures to allow for forming at constant force and forming at constant stress levels by modulating electric current to directly control material strength. These are demonstrated in a tensile forming operation, and found to produce the desired results. Combining these control approaches with previous and contemporary efforts in modeling of the process physics will allow for system identißcation of material response properties and model-based control of difficult-to-observe process parameters such as real time temperature gradients. Model-Based Manufacturing Process Control. Model-Based Control (MBC) is a term incorporating a number of approaches Journal of Manufacturing Science and Engineering

“…The EAM technique can be applied to various different manufacturing processes, including bulk deformation, sheet metal forming, and joining procedures. 2…”

Section: Introductionmentioning

confidence: 99%

Thermomechanical modeling sensitivity analysis of electrically assisted forming

Bunget

Salandro

Proceedings of the Institution of Mechanical Engineers, Part B:

2013

Recent research by the authors has resulted in the conception of several methods of accounting for direct electrical effects during an electrically assisted manufacturing process, where electricity is applied to a conductive workpiece to enhance its formability characteristics. This modeling and analysis strategy accounts for both mechanical effects and heat transfer effects due to the applied electrical power. This study presents a sensitivity analysis and explanation of several key material and process inputs during an electrically assisted forming test on Stainless Steel 304 and Titanium Grades 2 and 5 specimens. First, the effect that the specific heat ( Cp) value has on the model will be discussed and compared with another lightweight material. Second, the significance of all three heat transfer modes (conduction, convection, and radiation) will be noted, and any possible simplifications to the existing heat transfer model will be highlighted. Third, the general electroplastic effect coefficient profile shape for the Stainless Steel 304 material will be compared to that of titanium alloys. Fourth, a frequency analysis will be done on the data taken during the experiments, by way of a Fast Fourier Transform, and the variation of frequency response with the electric input is studied. Overall, this study provides insight into several factors affecting a material’s electroplastic effect coefficient profile and also compares resulting electroplastic effect coefficient profiles of various materials.