Effect Of Vibration On Filling Performance Of Aluminium Alloy Casting

In this thesis,the behaviors of mold-filling and solidification for ZL101 Aluminium casting were investigated under the condition of applying vibration force field,including the influence of the frequency and amplitude of vibration on the mold-filling of ZL101 Aluminium metal-mold casting as well as the influence on reduced risers and sprues.The changing rules of fluidity,grain size and alloy hardness of ZL101 alloy with the frequency and amplitude of the vibration were tested by means of vibrating device and self-designed mold.Experimental results show that: When the vibration frequency is in a range of 30Hz~35Hz and amplitude is 0.16 mm,the mold-filling of ZL101 aluminum alloy presents the optimal performance.Compared with the casting process without vibration,under vibration condition,the mold-filling ratio of each flow path increases 151.4%(2mm thick flow channel)and 132.7%(3mm thick flow channel)respectively.When the vibration amplitude is 0.16 mm,with the increasing of the frequency,the grain structure of ZL101 alloy presents a trend of continuous refining,and the hardness of the alloy gradually increases.When the vibration frequency is 30 Hz,the grain refinement effect of the alloy is the best and the hardness reaches maximum.The riser-reducing rule of ZL101 alloy castings was tested under the vibration condition by using the vibration device and the actual production mold of the factory.Research results show that: The AnyCasting simulation of the experimental sample mold filling solidification process and the actual casting of the sample show that the lower part of the risers presents a small amount of shrinkage defects under the casting condition without vibration.However,when a vibration with the frequency 30 Hz and 0.16 mm amplitude is utilized,the shrinkage inside of the casting specimens disappears.Then gradually reducedsample size of risers,when the riser of the sample is reduced 26.3%,shrinkage cavity defects present again at some lower risers.The same testfor the runners in the vibration and no vibration was carried out by reducing the cross-sectional area of runners in mold.,on the condition being absence of vibration,the mold-filling is insufficient.However,when a vibration with a frequency 30 Hz and amplitude 0.16 mm is employed,the mold-filling performance improves.And with the decreasing of cross-sectional area of the runners,when the sample runner is reduced by about 22.2%,the samples will appear the phenomenon of insufficient filling.Moreover,the influence factors of fluidity,gas evolution,grain refinement and the hardening mechanisms were analyzed.As a result,when a vertical direction vibration is applied,mold-filling property of ZL101 alloy fluid improves.This is beneficial to the floating and spilling of gas and impurities.Vibration is also help to crush the dendrite crystal,refine the grain size,as well as to increase the hardness of castings.In the aluminum alloy liquid filling solidification process,the vertical direction of the mechanical vibration with a frequency of 30 Hz and an amplitude of 0.16 mm is beneficial to improve the filling capacity of ZL101 aluminum alloy,and italso can reduce the design wall-thickness of the casting,riser,sprue and obtain the similar original corresponding mechanical properties without increasing wall-thickness,as well as reduce the consumption of casting materials,as to achieve "green manufacturing" effect.