High speed production method of wrought magnesium alloy sheets using semi-solid twin roll strip casting and its plastic characteristics in warm deep drawing

采用双辊连铸机进行了镁合金半固态辊带连铸的试验研究。人们已经认识到，如果用轻金属生产的半固态材料代替传统的钢铁产品，则半固态成形有助于减轻产品的总重量。然而，镁合金应用的问题主要还是与制造成本高有关。本文以AZ31、AZ91、AM50和AM60镁合金为试验材料，确定了适用于半固态辊带连铸的镁合金。通过对熔融材料温度、上下辊速度等可独立改变的因素进行调整，找到合适的制造条件。从熔融材料与辊体的接触条件出发，阐明了冷却条件和接触条件对成形的影响。此外，还对成品铸件的晶体进行了显微观察。实验发现，在25m/min的速度下，可以生产出厚度为2.5 ~ 4.0mm的镁片。研究还发现，采用半固态制造工艺生产的热轧铸镁板可用于塑性成形。为验证AZ31B镁合金辊带铸造工艺的可行性，研究了半固态辊带铸造后热轧镁合金板材的热深拉伸性能。通过改变镁液温度和轧制速度来寻找合适的制造条件。改变了热轧和热处理条件，考察了何种条件适合生产变形镁合金薄板。对变形镁合金的结晶进行了显微观察。研究发现，半固态辊带式铸造镁合金板材热轧后的温深拉深工艺极限拉深比可达2.7。少

An experimental approach has been performed to ascertain the effectiveness of semi-solid roll strip casting of magnesium alloys using a twin roll caster. It has been recognized that semi-solid forming contributes to lightening the total product weight if semi-solid material produced by light metals can be used to replace conventional iron and steel products. However, the problems of utilizing magnesium alloys are still mainly related high manufacturing cost. This means that improved quality must be balanced by economic validity In this experiment, magnesium alloy AZ31, AZ91, AM50 and AM60 were used to determine which were appropriate for use in semi-solid roll strip casting. Temperature of the molten materials, roll speeds at upper and lower rolls, which could be changed independently, were varied to find an appropriate manufacturing condition. Effects of cooling and contact condition on possible forming were clarified in terms of contact condition between molten material and roll. Als … More o, microscopic observation of the crystals of the finished casting has been performed. It has been found that magnesium sheet with 2.5 to 4.0mm thickness could be produced at a speed of 25m/min. It also found that the hot rolled cast magnesium sheets produced by semi-solid manufacturing process could be used for plastic forming.Warm deep drawability of magnesium alloy sheets that were hot-rolled after a semi-solid roll strip casting process was investigated to demonstrate the feasibility of roll strip casting of AZ31B magnesium alloy. The temperature of the molten magnesium, and the roll speeds were varied to find appropriate manufacturing conditions. Hot rolling and heat treatment conditions were changed to examine which condition would be appropriate for producing wrought magnesium alloys sheets. Microscopic observation of the crystals of the produced wrought magnesium alloys was performed. It has been found that a limiting drawing ratio of 2.7 was possible in the warm deep drawing process of the cast magnesium alloy sheets that were hot-rolled after a semi-solid roll strip casting process. Less