Study On Aluminum Alloy Foams Materials For Heat Dissapation By Water Evaporation

With the development of robot engineering technology,the traditional cooling model by circulating water is not adaptive,because its devices in space proportion are too large in some circumstances.Some scholars proposed to improve the water storage of the robot skeletal structure by using the latent heat of water evaporation to complete the cooling of the drive motor.Porous aluminum foams alloy with specific porosity can fit this requirement.In this paper,from the perspective of material design,using Na Cl as the poreforming agent,and 6061 aluminum alloy as the matrix material of powder metallurgy method,we researched the preparation of aluminum foams alloy,and characterized the mechanical properties and heat dissipation properties of materials with different pore parameters,and got the best heat treatment process parameters.About the preparation process,the better mixing time,cold pressure,sintering temperature,heat preservation time,and thermal pressure compression method has been chosen by the microstructure and mechanical properties of materials.The mechanical properties of materials with different porosity and pore size were characterized and analyzed.The actual open porosity was measured,and the simulated heat dissipation device was designed to characterize the heat dissipation performance of materials with different porosity.Orthogonal test was designed to analyze the effects of solid solution temperature,solid solution time,aging time and aging temperature on the mechanical properties of materials.The result shows that the material with uniform structure and stable performance can be obtained under 3:1 ratio of ball to powder,115r/min rotation speed and 4h mixing time.The optimum preparation process combination consists of 25 MPa cold pressing pressure applied by two-direction,10 min maintaining time,and two-step thermal pressure maintained for 5 min,and 630?sintering temperature with 30 min heat preservation.Under 79~526?m size,50% porosity of aluminum alloy foams tensile strength reached 27.98 MPa.The tensile strength of the material is directly affected by porosity and decreases linearly as porosity increases.The tensile strength of the material is slightly greater than the pore diameter due to the influence of pore morphology.The tensile strength of foamed aluminum prepared by larger size pore-forming agent is slightly better.The actual connection porosity is different from the design porosity.With the increase of the design porosity,the actual situation is closer to the design condition.When the heating power is constant,the higher the open-hole rate is,the lower the temperature of the system to achieve dynamic equilibrium and the stronger the heat dissipation capacity is.Material with better performance can be obtained after T6 heat treatment with 520? solid solution temperature maintained for 1h and 190? aging temperature maintained for 2h.