Ultrafast laser deposition of powder materials on glass

Abstract

The deposition of various powder materials on borosilicate glass was demonstrated using high-repetition-rate (frep = 1.5 MHz) femtosecond laser light. Melting of the glass substrate was caused by the heat-accumulation effect following multi-photon absorption, while powder materials were melted primarily through linear absorption. This novel processing approach allows the simultaneous melting of glass and powders leading to the formation of either a mechanical joint or fusion welds. The deposition of continuous material tracks was demonstrated for nickel, tin, stainless steel, copper, silicon, as well as silicon oxide powders. Effects of the varying average laser power and focus position on the deposited track morphology were studied. Laser-deposited tin and copper layers with thicknesses up to 60–70 µm were produced.