ECAP加工を施したMg-8 mass%Li 2相合金の超塑性
ECAP加工を施したMg-8 mass%Li 2相合金の超塑性
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DOI：
10.2320/jinstmet.70.729
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发表时间：
2006-09
影响因子：
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通讯作者：
光明 古井;Cheng Xu;哲夫 曾田;誠 井上;博之 穴田;Terence G. Langdon
中科院分区：
文献类型：
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作者：
光明 古井;Cheng Xu;哲夫 曾田;誠 井上;博之 穴田;Terence G. Langdon
采用内通道角为110°、挤压温度为473 K的模具进行等通道转角挤压（ECAP），对Mg-8 mass%Li合金进行了显著的相细化和弥散。挤压和ECAP两道次后，合金在423 ~ 473 K温度范围内表现出超塑性。当初始应变速率为1.0×10- 4s-1时，在473 K下获得了>950%的最大断裂伸长率。测得的应变速率敏感性为0.6的顺序。在相同的温度和应变速率下，与其他镁合金拉伸试验相比，最大延伸率较高。超塑性流动的激活能与Mg的晶界扩散激活能基本相等。ECAP的使用使室温下的强度和塑性得到显著改善。
Significant phase refinement and dispersion were achieved in a cast Mg-8 mass%Li alloy through processing by equal-channel angular pressing (ECAP) using a die having an internal channel angle of 110° and a pressing temperature of 473 K. Following extrusion and subsequent ECAP through 2 passes, the alloy exhibited superplasticity over the temperature range from 423 to 473 K. A maximum fracture elongation of >950% was attained at 473 K with an initial strain rate of 1.0×10-4 s-1. The measured strain rate sensitivity was of the order of 0.6. The maximum elongation is high in comparison with other Mg alloys tested in tension at the same temperature and strain rate. The activation energy for superplastic flow was essentially equal to the value for grain boundary diffusion of Mg. The use of ECAP gives a significant improvement in strength and ductility at room temperature.