(重慶大學 材料科學與工程學院,重慶 400044)
摘 要: 回顧了國內外近幾十年來關于Zircaloys合金中第二相粒子本征特征(晶體結構、成分、形狀、亞結構等)的相關研究工作。 Zircaloys合金中的Zr-Fe-Ni粒子只有一種,即C16(BCT,Al2Cu)型Zr2(Fe, Ni) Zintl相。而Zr-Fe-Cr粒子主要有兩種:一種是C14(HCP, MgZn2)型Zr(Fe, Cr)2 Laves相,另一種是C15(FCC, MgCu2)型Zr(Fe, Cr)2 Laves相,這些Laves相內部均可見層錯結構。歸納總結出形成溫度決定論、n(Fe)/n(Cr)決定論、價電子/原子比決定論3種理論,用于解釋Zr(Fe, Cr)2粒子形成穩(wěn)定結構的原因。常規(guī)加工工藝下,在Zircaloys合金成分范圍內,Sn完全固溶于α-Zr基體,不會參與形成析出相,Fe、Cr、Ni一般也不會單獨與Zr形成Zr-Fe、Zr-Cr、Zr-Ni粒子。
關鍵字: Zircaloys合金;Laves相;Zr-Fe-Ni粒子;Zr-Fe-Cr粒子
(College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China)
Abstract:In the recent decades the investigations about intrinsic characteristics (crystallographic structure, microchemistries, shape, substructure, etc.) of the second phase particles (SPPs) that might present in Zirclaoys were thoroughly reviewed. Some research experiences and approaches which would be of great help to the SPPs investigations for new-developed high-performance zirconium alloys are obtained. It can be summarized that in Zircaloys there is only one kind of Zr-Fe-Ni SPPs, i.e. C16 (BCT, Al2Cu) Zr2(Fe, Ni) Zintl phase. While for the Zr-Fe-Cr Laves SPPs in zircaloys, there are two variants. One is C14 (HCP, MgZn2) Zr(Fe, Cr)2 and the other is Laves phase with C15 (FCC, MgCu2) structure. Stacking faults were frequently observed by researchers in those Zr(Fe, Cr)2 SPPs. Based on a large amount of studies, it is summarized that the formation temperature, n(Fe)/n(Cr) ratios or valence electron/atom ratios of SPPs are determinant factors in respect to the stable structures of Zr(Fe, Cr)2. In addition, the possibility of presence of Sn-bearing particles was discussed as well as Zr-Fe, Zr-Cr and Zr-Ni particles in Zircaloys under conventionally processing conditions.
Key words: Zircaloys; Laves intermetallics; Zr-Fe-Ni particles; Zr-Fe-Cr particles


