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本文研究了微量稀土元素对QBe2合金组织与性能的影响。稀土微溶于α固溶体中,其余以Cu(Ce、La)相存在。稀土溶入α固溶体使其晶粒尺寸略增,β相数量减少,Be在α固溶体中高温溶解度增大。QBe2+0.1%RE合金经时效处理后的强度比QBe2合金提高约10%。稀土提高了各析出阶段的激活能,延缓了QBe2合金的时效析出过程。稀土减少了QBe2合金不连续析出的体积分数,使片层组织细化。稀土基本不改变不连续析出的形成温度范围。利用Sundquist不连续析出理论证实,稀土不改变QBe2合金不连续析出的晶界扩散机制,对不连续析出的抑制作用是由于改变了不连续析出前沿的θ′参数值,减小了相变驱动力。
In this paper, the effects of trace rare earth elements on the microstructure and properties of QBe2 alloy were studied. Rare earths are slightly soluble in α solid solution, and the rest is Cu (Ce, La) phase. Rare earth into the α solid solution makes its grain size slightly increased, the number of β-phase decreases, Be in α solid solution at high temperature solubility increases. The strength of QBe2 + 0.1% RE alloy after aging treatment is about 10% higher than that of QBe2 alloy. Rare earths increase the activation energy of each precipitation stage, delaying the aging precipitation process of QBe2 alloy. REE reduces the volume fraction of discontinuous precipitation of QBe2 alloy, refining the lamellar structure. Rare earth basically does not change the formation of discontinuous precipitation temperature range. Using Sundquist discontinuous precipitation theory, it is confirmed that the rare earth does not change the grain boundary diffusion mechanism of discontinuous precipitation of QBe2 alloy, and the inhibition effect on discontinuous precipitation is due to the change of the θ ’parameter value of the discontinuous precipitation front and the reduction of the phase change driving force .