Electrodeposited Fe–Ga Alloy Films for Directly Coupled Noncontact Torque Sensing

Abstract

Torque measurements are used in a number of controls applications, but indirect coupling, size, and the quality of commercially available sensor materials can limit their utility. Here, a compact magnetostrictive torque sensor is made by electrodeposition of Fe 1−x Ga x (0.1<x<0.4, aka Galfenol), onto Cu shafts using rotating cylinder electrodes (RCEs). The alloy composition is controlled by tuning the RCE rotation rate between 500 and 2000 RPM, while the electrode potential is varied from 1.15 to 1.20 V. Direct coupling of Fe 1−x Ga x to the shaft with the electrodeposition process enables magnetic anisotropy to be induced via shaft surface texturing, as seen by a 260% increase in susceptibility along a 400 grit texturing direction versus perpendicular to the texture and compared with the isotropic behavior of films deposited on polished shafts. Inverse magnetostriction-based torque sensing is demonstrated by measuring stray fields from Fe 1−x Ga x films as torque loads of 0-16.9 Nm were applied to the shaft. Films electrodeposited on circumferentially textured shafts had torque responses almost 1.5 times greater than films electrodeposited on longitudinally textured shafts and five times greater than films on polished shafts.

Strain Sensing Technology to Enable Next-Generation Industry and Smart Machines for the Factories of the Future: A Review

“…This design can be vital in creating fault-diagnosis intelligent systems and analyzing the mechanical power of classical drive shafts to reveal transmission efficiency and operating conditions. Recently, Hein et al [350] achieved a successful magnetostrictive torque measurement approach applicable to several applications in rotary machines. Using Galfenol and rotating cylinder electrode (RCE) deposition, the sensing element was fabricated circumferentially, leading to a 260% increase in susceptibility and a 150% increase in torque response.…”

Fabrication and Characterization of Carbon Fiber Reinforced Plastics Containing Magnetostrictive Fe-Co Fibers with Damage Self-Detection Capability

“…Calkins et al have reviewed that Terfenol-D can be widely utilized as a sensor [6]. Fe-Ga alloy, known as Galfenol, also exhibits large magnetostriction, and Hein et al have studied its characteristics as a toque sensor [7]. Recently, Li et al have studied (Fe 83 Ga 17 ) 99.4 B 0.6 wires of 0.5 mm diameter which were prepared by hot forging, rolling and combining hot and cold drawing [8].…”