Researchers in the US have found a previously unknown type of metal deformation and a method to suppress it that could make life easier for manufacturers.
The researchers from Purdue University say that the discovery of the metal deformation called ‘sinuous flow’ could lead to new opportunities in a range of manufacturing applications that involve metal deformation such as in machining, stamping, forging and sheet-metal processes.
The team discovered the phenomenon by using high-speed microphotography and analysis to study what happens while cutting ductile metals. They found that the metal is deformed into folds while it is being cut – contrary to long-held assumptions that metals are sheared uniformly – and also that sinuous flow can be controlled by suppressing this folding behaviour.
"When the metal is sheared during a cutting process it forms these finely spaced folds, which we were able to see for the first time only because of direct observation in real time," one of the team members, Ho Yeung said.
Findings showed the cutting force can be reduced 50 percent simply by painting metal with a standard marking ink.
Because this painted layer was found to suppress sinuous flow, the implications are that not only can energy consumption be reduced by 50 percent but also that machining can be achieved faster and more efficiently and with improved surface quality, according to professor of industrial engineering Srinivasan Chandrasekar.
The findings – which may also prove useful for making armour, vehicles and structures – are detailed in a research paper appearing in Proceedings of the National Academy of Sciences.