Microstructure and properties of a refractory NbCrMo0.5Ta0.5TiZr alloy
Microstructure and properties of a refractory NbCrMo0.5Ta0.5TiZr alloy
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DOI：
10.1016/j.msea.2011.09.033
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发表时间：
2011-11-25
期刊：
影响因子：
6.4
通讯作者：
Woodward, C. F.
中科院分区：
文献类型：
--
作者：
Senkov, O. N.;Woodward, C. F.
采用真空电弧熔炼法制备了一种新型的高熔点合金Nb（20）Cr（20）Mo（10）Ta（10）TinZr（20）。为了消除缩松，在T = 1723 K和P = 207 MPa下热等静压（HIPd）3 h。在凝固和热等静压条件下，合金均含有三个相：两个体心立方相（BCC 1和BCC 2）和一个面心立方相（FCC）。BCC 1相富集Nb。Mo和Ta，并且耗尽Zr和Cr，并且其在HIP之后的晶格参数为a = 324.76 +/- 0.16 pm。BCC 2相富含Zr和Ti，并且相当程度地贫含Mo。Cr和Ta，并且其在HIP之后的晶格参数估计为a = 341.0 +/- 1.0 μ m。FCC相高度富集Cr，并且其被鉴定为Laves C15相，（Zr，Ta）（Cr，Mo，Nb）（2），具有晶格参数a = 733.38 +/- 0.18 μ π ι。BCC 1、BCC 2和FCC相的体积分数分别为67%、16%和17%。合金密度和维氏显微硬度分别为rho = 8.23 +/- 0.01 g/cm（3）和H-upper = 5288 +/- 71 MPa。该合金在296 K时的压缩屈服强度为1595 MPa，在1073 K时为983 MPa，在1273 K时为546 MPa，在1473 K时为171 MPa。在296 K和1073 K的变形过程中，该合金在类似于5- 6%的塑性压缩应变后显示出韧性和脆性断裂的混合物。在1273 K和1473 K下，50%压缩应变后没有观察到宏观断裂。在1073-1473 K温度范围内，塑性变形显著加速了相变和颗粒粗化。(C)2011 Elsevier B. V.保留所有权利。
A new refractory alloy, Nb(20)Cr(20)Mo(10)Ta(10)TinZr(20), was produced by vacuum arc melting. To close shrinkage porosity, it was hot isostatically pressed (HIPd) at T = 1723 K and P = 207 MPa for 3 h. In both as-solidified and HIPd conditions, the alloy contained three phases: two body centered cubic (BCC1 and BCC2) and one face centered cubic (FCC). The BCC1 phase was enriched with Nb. Mo and Ta and depleted with Zr and Cr, and its lattice parameter after HIP was a = 324.76 +/- 0.16 pm. The BCC2 phase was enriched with Zr and Ti and considerably depleted with Mo. Cr and Ta, and its lattice parameter after HIP was estimated to be a = 341.0 +/- 1.0 pm. The FCC phase was highly enriched with Cr and it was identified as a Laves C15 phase, (Zr,Ta)(Cr,Mo,Nb)(2), with the lattice parameter a = 733.38 +/- 0.18 pm. The volume fractions of the BCC1, BCC2 and FCC phases were 67%, 16% and 17%, respectively. The alloy density and Vickers microhardness were rho = 8.23 +/- 0.01 g/cm(3) and H-upsilon = 5288 +/- 71 MPa. The alloy had compression yield strength of 1595 MPa at 296 K, 983 MPa at 1073K, 546 MPa at 1273 K and 171 MPa at 1473 K. During deformation at 296K and 1073 K. the alloy showed a mixture of ductile and brittle fracture after plastic compression strain of similar to 5-6%. No macroscopic fracture was observed after 50% compression strain at 1273K and 1473K. Phase transformations and particle coarsening considerably accelerated by the plastic deformation occurred in the temperature range of 1073-1473 K. (C) 2011 Elsevier B.V. All rights reserved.