Effects of amplified spontaneous emission on laser shock processing 7050 aluminium alloy

The 7050 aluminum alloy was processed by laser shock processing (LSP) with high energy repetition rate Nd:glass laser. With unchanged pump power, pressure waveform was measured by polyvinylidene fluoride (PVDF) and the oscilloscope, the surface residual stress of 7050 aluminum alloy was measured by X-ray diffraction, surface roughness was analysed by non-contact optical profiler, the micro-mechanism of the shock pressure, the residual stress and roughness was studied after LSP. Results show that under the condition of unchanged pump power, with the increase of amplified spontaneous emission, the shock pressure and the compressive residual stress of the sample surface gradually decrease, the surface roughness gradually increase.