含Nb或Cu的锆合金显微组织研究

Microstructure of Zr Alloy Containing Nb or Cu Element

用TEM和SEM研究了含少量Nb或Cu的锆合金显微组织,结果表明:在微量Fe元素存在时,添加适量Cu元素,会促使低于α-Zr中平衡固溶含量的Nb元素与Fe元素优先析出形成沉淀相,致使α-Zr中Nb的固溶含量更低;若增加Cu元素含量,因Zr_2Cu第二相富集消耗了Fe元素,反而使Nb元素不易析出。在Zr-1.0Cu合金中加入适量的Nb元素,可以细化Zr_2Cu第二相的尺寸,促使其分布更加均匀。在大量Nb稳定的β-Zr第二相存在的情况下,添加的少量Cu会富集在β-Zr第二相中,而不会以Zr_2Cu第二相形式析出。

The effect of Nb and Cu on the microstructure of Zr alloys was investigated by TEM and SEM. Results show that when a trace amount of Fe element is presented, the precipitation of Nb and Fe, whose amount is below the equilibrium solid solution limitation in α-Zr, are promoted by adding the appropriate amount of Cu element, leading to the lower content of Nb in α-Zr alloys. However, the precipitation of Nb-enriched phase is inhibited by the further addition of Cu amount since the Fe element is consumed by the enrichment of Zr_2Cu phase. Meanwhile, Zr_2Cu phase in Zr-1.0Cu alloy is significantly refined and uniformly distributed after the addition of Nb element. In the presence of β-Zr secondary phase stabilized by a large amount of Nb element, a small amount of Cu element is enriched within the β-Zr phase rather than being precipitated as Zr_2Cu.