Shear band formation in shaped rheocast aluminium component at various plunger velocities  

作　　者：M.BLADH M.WESSN A.K.DAHLE 

机构地区：[1]Swerea SWECAST AB [2]Materials and Manufacturing-Casting,School of Engineering,Jnkping University [3]Materials Engineering,The University of Qu eensland

出　　处：《Transactions of Nonferrous Metals Society of China》2010年第9期1749-1755,共7页中国有色金属学报（英文版）

摘　　要：Significant progress has been made in recent years in understanding and modelling the rheology of semi-solid metals.These models show the effects of the microstructure in terms of size and morphology of globules on the material response.More recently it has been shown that semi-solid metals can behave as compacted granular materials such as sand.A particular signature of such deformation is that the deformation becomes concentrated into shear bands which are 10-20 grains wide.Such bands have also been observed in a range of cast products.Recently, it has been clearly shown that shear bands in high pressure die cast (HPDC) products are also the results of Reynolds dilatancy.Shear bands are also known to be a common feature in semi-solid metal products.The segregation banding in semi-solid metal (SSM) material and its dependence of plunger velocity were investigated.Shaped castings were made with the RHEOMETALTM process with a range of different plunger velocities.The microstructural characteristics were investigated, with a particular emphasis on shear bands.It is shown that ingate velocities influence the location and characteristics of the shear bands.Significant progress has been made in recent years in understanding and modelling the rheology of semi-solid metals. These models show the effects of the microstructure in terms of size and morphology of globules on the material response. More recently it has been shown that semi-solid metals can behave as compacted granular materials such as sand. A particular signature of such deformation is that the deformation becomes concentrated into shear bands which are 10-20 grains wide. Such bands have also been observed in a range of cast products. Recently, it has been clearly shown that shear bands in high pressure die cast （HPDC） products are also the results of Reynolds dilatancy. Shear bands are also known to be a common feature in semi-solid metal products. The segregation banding in semi-solid metal （SSM） material and its dependence of plunger velocity were investigated. Shaped castings were made with the RHEOMETAL^TM process with a range of different plunger velocities. The microstructural characteristics were investigated, with a particular emphasis on shear bands. It is shown that ingate velocities influence the location and characteristics of the shear bands.

关 键 词：RHEOCASTING shear bands SEGREGATION AL-ALLOYS RHEOMETAL^TM 

分 类 号：TG292[金属学及工艺—铸造]