The Effect Of Refiner Al-5Ti-B And Modifier Al-10sr On The Quality Of Aluminum Liquid And Products

Based on typical A356.2 alloy as the main research object,research in the process of low pressure casting,refiner aluminum titanium boron,inoculant aluminum strontium addition amount,temperature and stirring speed of aluminum alloy wheel hub different location of the organization structure,mechanical properties,etc.Refining agent was put forward and the optimal formula of inoculant addition amount and stir in the optimal rotor speed.Selected four kinds of different ratio of aluminum titanium boron refining agent and aluminum strontium metamorphism agent is tie-in,the aluminum strontium and titanium boron directly into ladle,the ladle liquid aluminum production hub for the corresponding microstructure observation,mechanical property test and reliability test.The test results show that the optimum proportion of aluminum titanium boron/aluminum strontium join for aluminum titanium boron addition amount of 2.5kg,1.5kg for the amount of aluminum strontium.Under the proportion of liquid aluminum,after low pressure casting and heat treatment to obtain the hub of tiny grains,eutectic Si a round rod,and with the best mechanical properties as well as the process of product performance.When refining agent content relative to the metamorphic agent content is high,the Sr and refining agent B reaction to generate the Sr4 B,reduces the bad effect of Sr,enables the eutectic Si not to form a uniform short clavier form.Cause the loss of mechanical properties.Four kinds of refining agent and modifier ratio or output of liquid aluminum alloy wheel hub,all can pass the reliability test.In the optimal proportion of refining agent and modifier,using three different stirring speed probe refining agent and modifier to join after stirring speed on the quality of the aluminum alloy wheel hub,used to get the best degassing refining process.Test results show that when the degassing rotor speed at 400 RPM,substrate alpha Al size is larger,and the distance between the secondary dendrite,eutectic Si phase present a rod,and observed in visual range of eutectic Si phase bias.When degassing rotor speed from 400 RPM to 600 RPM,alpha Al phase average size is small,the secondary dendrite grow up is not obvious,and the eutectic Si phase present a short clavite evenly distributed on the matrix.When degassing rotor speed up to 800 RPM,the hub of the microstructure and mechanical properties when compared to the rotor speed is 600 RPM of ascension is not obvious,this shows that in addition to air the speed of the rotor has certain limits,not rotation rate is higher,the degassing effect more obvious,and the rotation speed of the high will reduce the service life of the rotor of the degassing.Considering the cost of production and the quality of liquid aluminum degassing rotor rotating speed should be 600 RPM.