| Friction surfacing was a solid-phase joining technology based on thermoplastic deformation,which could refine the grain in the weld zone and obtain a weld overlay layer with substantially no dilution and high integrity.Friction surfacing had unique advantages such as low cost,high efficiency,high processing quality and low energy environmental protection.Friction surfacing was significant in friction rolling,rapidly manufacturing of parts and composite material preparation.AA5083 aluminum alloy and DH36 steel were taken as research objects in this paper.The influence of process parameters and consumable diameter on the appearance and appearance of consumables and substrates,contact pressure,temperature of the center point of the contact surface and bonding strength were investigated.At the same time,the coating and substrate were studied.The metallographic structure and microhardness near the interface were simulated.The CEL method in ABAQUS finite element software was used to simulate the friction surfacing.The influence of process parameters and consumable diameter on the axial force?temperature of the center point of the contact surface?heat generated by the friction and plastic deformation was investigated.The experimental and simulation results showed that in the plunge stage of friction surfacing,the higher the rotational speed,the smaller the axial force,the higher the temperature at the center of the contact surface;the higher the feed rate,the higher the axial force and temperature of the contact point center point;the larger the diameter of the consumable,the higher the axial force and the center point temperature;the farther the bottom of the consumable was from the center point,the smaller the contact pressure;the shape of the temperature distribution from the center of the consumable to the edge was similar to the normal distribution,the intermediate temperature was higher,and the temperature at the center and edge of the consumable was lower.The simulation of the plunge stage of friction surfacing showed that the rotation speed was higher,the feed rate was larger,and the diameter of the consumables was larger,the heat generated by the friction and plastic deformation were larger.The higher the rotational speed,the greater the heat generated by the friction and plastic deformation;the higher the feed rate,the greater the heat generated by the friction and plastic deformation;the larger the diameter of the consumables,the greater the heat generated by the friction and plastic deformation.The experimental results of the friction welding surfacing stage indicated that the higher the rotation speed,the smaller the axial force?contact pressure?temperature at the center of the contact surface and the shear strength;the lower feed rate,the larger the axial force?contact pressure?temperature and the shear strength;the welding speed had little effect on the axial force and temperature,but the shear strength was the highest when the welding speed was 80mm/min;the larger the diameter of the consumable,the larger the axial force,the smaller the contact pressure.The temperature at the center of the contact surface and shear strength were higher when the diameter was 24 mm;the bonding strongest part of the coating and the substrate was located near the trajectory line passing through the center point below the consumable;The greater the axial force,the thinner the coating;when the axial force was the same,the lower the weld speed,the thicker the weld overlay.The middle of the coating was thinner and thicker on both sides.The coating on the retreating side was higher than the advancing side,and the position of the coating near the flashing edge had a bonding defect because the contact force was too low in this position.The high stress and high temperature during the friction surfacing process change the microstructure of the steel at the interface.The ferrite grains were elongated along the interface direction,and the microhardness of the steel immediately adjacent to the interface was higher. |
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