| 1100 aluminum alloy is widely used in many fields from cooker to industrial equipment due to excellent processing properties,corrosion resistance and properties in weld.Grain refiner is more effective to improve properties of 1100 aluminum alloys,however,overmuch use of grain refiner will increase the cost of production,at the same time,TiB2 phase in refiner agent tends to gather and deposit,which will pollute the melt and affect the quality of product.Thus,the usage of refiner should be moderate and effective to improve the alloy properties.In the present study,static magnetic field,pulse current and electromagnetic fields were applied to twin-roll casting of 1100 aluminum alloy respectively,the effects on microstructure and segregation were studied in the condition of different content of Al-Ti-B refiner with external physical fields.Several conclusions were attained as follows.(1)The microstructure that were obtained by twin-roll casting process were similar with the casting,all that consisted of ultra-fine crystal zone in the surface,center equiaxed crystal zone and columnar crystal zone in between them.However,in TRC process,the structure near the lower surface of sheet were finer than near the upper surface;(2)All different external physical fields were effective to refine grains during TRC process,while action of the combined fields was the most prominent;(3)The segregation of in 1100 aluminum alloy sheets were restrained by external physical fields.The combined fields were most effective;(4)When the content of Al-Ti-B is less than 0.4%,effect of grain refinement is more and more obvious with the increase of the refiner;(5)Refinement effect of 0.1%Al-Ti-B with combined fields in TRC process is more than content of 0.4%in typical TRC process;(6)Under existing experimental conditions,the segregation of aluminum sheets was lightest when pulse current of 30Hz frequency,peak current of 250A and static magnetic field of 26mT induction intensity were combined. |
PDF Full Text Request