Construction Of Wire Arc Additive Manufacturing Experimental Platform Simulating Shipboard Environment And Research On Forming Law

Because of its advantages of high deposition efficiency,large forming size and relatively low manufacturing cost,Wire Arc Additive Manufacturing(WAAM)has become the primary choice for rapid repair of parts on large ships or offshore platforms.However,due to the problems of hull vibration and sway at sea,the influence law of vibration and sway on WAAM forming is not clear,and the relevant research is relatively few.Therefore,the realization of shipboard Wire Arc Additive Manufacturing still faces many difficulties.In this paper,the effects of vibration,sway and vibration+sway on WAAM forming are systematically studied by building an experimental platform simulating ship environment.The main research contents are as follows:1.Building an experimental platform to simulate the shipborne environment.Using vibration platform,rocking platform and welding equipment,an experimental platform which can realize three states of vibration,rocking and vibration+rocking is built,which can meet the experimental requirements.2.Influence law of vibration on WAAM forming.The effects of different vibration frequencies and amplitudes on the forming quality,grain size and mechanical properties of single-layer single pass and multi-layer single pass thin-wall were studied.It is found that when the frequency and amplitude are large,the morphology quality of single pass and thin wall becomes obviously worse,the single pass melting height H and melting width W increase and decrease in varying degrees,and the penetration depth D decreases by 43.5%.For thin wall,the maximum effective width decreases by 17.8%,the effective height increases and decreases in varying degrees,the maximum increases by 11.4%,the minimum decreases by 16%,and the maximum effective utilization rate decreases by 14.1%.On the whole,most of the grain sizes are basically smaller than the steady state,the difference between the tensile strength and the steady state is no more than 2%,the yield strength increases by 5.5%and the elongation increases by 16.7%.3.Influence law of swaying on WAAM forming.The effects of different rocking frequencies on the forming quality,grain size and mechanical properties of single-layer single pass and multi-layer single pass thin-wall were studied.It is found that when the frequency is large,the morphology quality of single pass and thin wall becomes obviously worse,the maximum melting height H increases by 10.5%,the melting width W increases and decreases in varying degrees,the maximum increases by 7.4%,the minimum decreases by 4.7%,and the penetration D also increases and decreases in varying degrees,the maximum increases by 7.5%and the minimum decreases by 30.8%.For thin wall,the maximum effective width increases by 8.4%,the maximum effective height increases by 25.4%,the maximum effective utilization increases by 29.2%,the maximum grain size increases by 27.8%,the maximum tensile strength increases by 2%,the maximum yield strength decreases by 5.2%,and the maximum elongation decreases by 18.5%.4.Influence law of vibration+sway on WAAM forming.The effects of vibration+rocking on the forming quality,grain size and mechanical properties of single-layer single pass and multi-layer single pass thin-wall are studied.It is found that vibration and rocking are not simple superposition.On the contrary,there is no obvious change in the morphology quality of single pass and thin-wall after coupling.In the state of vibration+rocking,the single pass melting height H decreases by 8%and the melting width W increases and decreases in varying degrees,The maximum increases by 6%,the minimum decreases by 1.6%,and the penetration D also increases and decreases in varying degrees,the maximum increases by 17.5%and the minimum decreases by 8.9%;For thin wall,when the frequency is less than 1.67hz,the fluctuation of effective width is very small,which is about 8.53mm.When the frequency is less than 1.67hz,the effective width is less than the steady state.On the whole,the maximum effective width increases by 9.3%,the minimum decreases by 5.3%,the maximum effective height decreases by 11.2%,the maximum effective utilization rate increases by 5.2%,the grain size increases in varying degrees,and the maximum tensile strength increases by 2.2%,The minimum yield strength decreased by 18.5%and the maximum elongation decreased by 16.1%.