Study On Strengthening Mechanism Of 7A04 Aluminum Alloy By Laser Shock Implantation Of SiC Nanoparticles

Laser shock-wave driven nanoparticle implantation(LSPWN)is a new surface strengthening method proposed in recent years.It is based on laser shock strengthening technology and uses high-energy short-pulse laser radiation to irradiate the metal surface coated with nanoparticles.Nanoparticles are implanted into the strengthened matrix to form a strengthened layer,which can effectively improve the mechanical properties of metal materials and enhance their resistance to wear and corrosion.It has become the research frontier of laser shock peening technology,but its strengthening mechanism has not yet been explored clearly.In order to explore the strengthening mechanism of laser shock implanted nanoparticles,this paper changes the time-domain characteristics of the input pulse laser,and uses single pulse laser and delayed pulse laser as energy sources.The mechanism research on the strengthening of 7A04 aluminum alloy by laser shock implantation of nano silicon carbide particles was carried out.In terms of theoretical research,the physical process of laser ablation of aluminum foil to generate plasma and plasma shock wave was analyzed by combining the theory of fluid mechanics and plasma theory,and the simulation model of laser shock implantation of Si C nanoparticles was built by combining the theory of pressure distribution of laser shock,and the depth of implantation of pulsed laser and delayed pulsed laser shock was simulated.It is also simulated that the implantation depth of nanoparticles is more difficult with the increase of laser energy,and the implantation depth of double pulse laser is more advantageous under the same energy.In terms of theoretical research,combined with fluid mechanics theory and plasma theory,the physical process of laser ablation of aluminum foil to generate plasma and plasma shock wave was analyzed,combined with the pressure distribution theory of laser shock,a simulation model for laser shock implantation of nano-Si C particles was constructed.Simulate the depth at which pulsed and delayed pulsed laser shocks implant nanoparticles.Through simulation,the benefit of nanoparticle implantation depth decreases with the increase of incident energy,and the delayed pulse laser is more advantageous at the same energy.In terms of experiments,the experimental research of laser shock implantation of nano-silicon carbide particles to strengthen 7A04 aluminum alloy and the speed research experiment of plasma shock wave induced by delayed pulse laser and nanosecond pulse laser ablation of aluminum foil were carried out.It is measured that the single-pulse laser plasma shock wave basically expands in a semicircular shape,and the initial velocity of the shock wave is slightly higher than the speed of sound,and then drops rapidly after a period of time;the delayed pulse laser plasma shock wave has a higher velocity in the direction of the vertical incident laser,and The unit time displacement and expansion velocity in the incident direction of the laser are greater than those of the nanosecond pulse plasma under the same energy condition;under the same energy,the wave velocity of the plasma shock wave induced by the delayed pulse laser is higher than that of the single pulse,and the delayed pulse laser shock implantation In the nano-Si C characterization diagram,the degree of dispersion of nano-Si C has been significantly improved.This paper explores the strengthening mechanism of laser shock implanted nanoparticles from the perspective of plasma shock wave,which provides a reference for the optimization of delayed pulse laser in the field of LSPWN.