The Bending Forming Mechanism of Copper Alloy by Different Lasers

Abstract

By FEA method, the bending of the copper alloy thin-plates by continuous laser forming (CLF) and pulse laser forming (PLF) was studied. Based on the analysis of dynamic change and steady distribution for the fields of temperature, stress/strain and displacement, the forming mechanism and rule of copper alloy by different laser modes were revealed. The whole deformation of PLF was the additive effect of all impulse action, while CLF mainly was the result of thermal stress. To get the same deformation, laser pulse energy is about 6 times of the continuous laser，CLF is suitable for larger deformation demands, and PLF is more seemly for micro-forming.

Laser Forming for Complex 3D Folding

“…The ability to fine tune position in laser forming with repeated laser passes is a major advantage over surface‐tension‐driven self‐folding based on actual melting through high energy plasma exposure, which also requires prepatterning and highly specialized equipment . Although most commonly for metals, with examples including nickel–titanium shape memory alloys, stainless steel, and copper in addition to the nickel in this work, the folding technique has also been demonstrated for silicon and ceramics . Polymers can also be folded through laser‐induced heating but folding in those cases typically results from heat‐induced softening or strain relaxation at the glass transition temperature rather than the inelastic strains of laser forming.…”

Self‐Folding Metal Origami

“…Based on simple thermal expansion and the resulting plastic stress buildup, laser forming can be performed on a relatively broad material set. Numerous metals have been laser formed such as aluminum, titanium, nickel, stainless and other steels, copper alloys, and nickel‐titanium shape memory alloy . Although rarer, there have been demonstrations in nonmetals such as crystalline semiconductors and glass and ceramics .…”

Making Light Work of Metal Bending: Laser Forming in Rapid Prototyping

“…Since its first reports, laser forming has been used to bend sheets of common metals, such as stainless steel [67][68][69] and aluminum [70][71][72], out of plane without mechanical inputs [36,37,67]. As the understanding of the process developed, more varied substrates were explored such as titanium, [27,73] and copper alloys [74,75], hoping to develop new ways to form 3D structures for aerospace and electrical applications. Researchers have also explored laser forming on non-metallic substrates and have bent typically brittle materials such as silicon [76][77][78], ceramics [41,79], and glass [79,80].…”

“…Critical to the success of the laser forming process is appropriate coupling of the laser energy to the material being formed. This coupling can be achieved by selecting the appropriate laser wavelength that corresponds to the absorption maximum of the substrate [75,88], by using a much higher power laser, so sufficient energy is absorbed by the substrate even with low absorptivity, or by using an absorbing coating layer that is matched with the laser wavelength being used ( Figure 6) [85,89]. Metals thicker than 100 nm are optically opaque [90] and do not transmit appreciable amounts of light, so the metal substrates that have been used in laser forming will primarily either reflect or absorb the laser energy.…”