AMRC experts have collaborated with the University of Sheffield’s Department of Mechanical Engineering on a new paper investigating the impact of remote laser processing on the mechanical and magnetic properties of electrical steels.

Dr Lloyd Tinkler, AMRC senior technical fellow and Dr Alexei Winter, AMRC technical lead for electrical machines collaborated with University of Sheffield researchers Dr Luke Jones, Professor Geraint Jewell and Professor Hassan Ghadbeigi on a research article titled, ‘Influence of Remote Laser Cutting on Magnetic Loss and Mechanical Properties in 0.2 mm Silicon Steel’. The results provide insights into the remote laser cutting process and its potential for commercial application in the production of laminated cores for electrical machines.

Silicon steels are the most common material used for electric machines. The cores of electrical machines are typically made from many hundreds of thin, insulated thin sheets or laminations of silicon steel to enhance flux density and reduce eddy current losses.

Energy loss due to eddy current generation is a significant factor in reduced efficiency of electrical machines, driving a trend for thinner laminations. While thinner gauges provide better functional performance, conventional stamping methods for these sheets become challenging because of the associated difficulties in handling thin, brittle parts and manufacture of low tolerance tooling. 

Conventional laser cutting is widely used for prototyping and low volume manufacturing, however, it is too slow to be commercially viable at larger production volumes. On the other hand, remote laser cutting offers higher speeds due to its lower inertia, prompting researchers to explore it as an alternative method in this research article. 

The research paper investigates the effect of remote laser cutting on the magnetic and mechanical properties of commercial thin electrical steel sheets (0.2 mm Cogent/Tata Steel NO20 3.2% Si). The influence of laser power and consequent thermal damage accumulation on the magnetic permeability, tensile and fatigue properties were studied. 

Read the full research paper here.