富铜基块体非晶合金的设计、制备与性能研究

发布时间：2018-05-23 21:59

  本文选题：铜基块体非晶合金 + 成分设计　； 参考：《东南大学》2015年博士论文

【摘要】：Cu基块体非晶合金具有优异的力学、物理及化学性能,是当前高性能先进金属材料的研究热点。目前国内外学者对块体非晶合金,尤其是多元块体非晶合金的非晶形成能力预测方法认识还不够。而在性能方面,现阶段的研究对于材料的塑性变形能力与合金耐腐蚀性能的研究仍不够深入。因此,本文从Cu基块体非晶合金的成分设计入手,利用相图热力学数据,预测多元Cu基非晶合金成分的凝固过程,并依据合金化技术手段构建块体非晶合金及其复合材料,改善其塑性变形能力。使用X射线衍射、示差扫描量热及微观组织分析表征了合金的非晶本质,同时研究合金化元素和紫外光辐照对块体非晶合金电化学腐蚀行为的影响。通过统计T_m与T_g之间的线性关系,将非晶形成能力参数T_rg=T_g/T_1合理地变换成T_rg=κT_m/Tl+C/T_1,该式反映了固相线温度T_m也是影响非晶形成能力的重要参数,同时也揭示了液相线温度Tt对非晶形成能力的重要作用。另一方面,该将参数T_rg从后验性参数转换成预测性参数,可以用于预测具有较高非晶形成能力的合金成分。同时,该参数揭示了合金的凝固温度区间对该合金的非晶形成能力的影响规律。根据该规律,设计并制备了多种三元Cu-Zr-Ti和Cu-Zr-Al系块体非晶合金。本论文设计的三元Cu-Zr-Ti块体非晶合金中,Ti元素含量范围在7.5-8.5at.%之间的块体非晶合金具有较大的塑性。通过热力学计算与合金凝固过程预测,并添加合金元素制备了三类四元块体非晶合金。Cu-Zr-Ti-Ni系合金中的Cu_(54.5)Zr_(37)Ti_8Ni_(0.5)、Cu-Zr-Ti-Si 合金中的 Cu_(54.5)Zr_(37)Ti_8Si_(0.5)、Cu_(53.5)Zr_(37)Ti_8Si_(1.5)表现较大的塑性变形能力。另外,通过分析组元间二元相图,选取了Mo、Nb和Hf元素分别取代Cu_(50.2)Zr_(40.8)Ti_9块体非晶合金中的Ti元素,Cu_(50.2)Zr_(40.8)Ti_8Mo_(1.0)、 Cu_(50.2)Zr_(40.8)Ti_8Nb_(1.0)和Cu_(50.2)Zr_(40.8)Ti_8Hf_(1.0)在各自的体系内均表现出最好的塑性和断裂强度。在本论文设计的所有合金中,Cu_(50)Zr_(42.5)Ti_(7.5)、Cu_(51.7)Zr_(40.8)Ti_(7.5)、 Cu_(54.5)Zr_(37)Ti_8Ni_(0.5)、Cu_(50.2)Zr_(40.8)Ti_8Nb_(1.0)和Cu_(50.2)Zr_(40.8)Ti_7Nb_(2.0)合金的压缩塑性和断裂强度分别超过了10%和2000 MPa。通过纳米压痕研究了塑性差别明显的两类块体非晶基复合材料的压痕蠕变行为,发现了合金的塑性与非晶基体的结构密切相关。添加合金元素Al、Ni、Si、Mo、Nb和Hf均可以提高Cu-Zr-Ti块体非晶合金的腐蚀电位。另一方面,Cu_(54.5)Zr_(37)Ti_8Si_(0.5)合金的腐蚀电流密度明显低于Cu_(55)Zr_(37)Ti_8。采用紫外光辐照,研究了两种Cu基块体非晶合金电化学腐蚀行为。动态极化曲线、电化学阻抗谱分析表明：Cu基块体非晶合金在紫外光辐照情况下腐蚀电流密度(腐蚀速率)降低和耐点蚀能力提高。通过观察腐蚀表面形貌,发现Cu基块体非晶合金在紫外光辐照条件下,点蚀位置较少且点蚀面积较小,证实了Cu基块体非晶合金在紫外光辐照的环境中具有高的耐点蚀能力。
[Abstract]:Cu based bulk amorphous alloys have excellent mechanical, physical and chemical properties. It is a hot topic in the current research of high performance advanced metal materials. At present, scholars at home and abroad are not aware of the prediction methods for the amorphous forming ability of bulk amorphous alloys, especially bulk amorphous alloys. The research on the properties of the deformability and corrosion resistance of the alloy is still not deep enough. Therefore, this paper, starting with the composition design of the Cu based bulk amorphous alloy, predicts the solidification process of the component of the multivariate Cu base amorphous alloy by using the thermodynamic data of the phase diagram, and builds the bulk amorphous alloy and its composite by means of alloying technology to improve its plastic deformation. The amorphous nature of the alloy was characterized by X ray diffraction, differential scanning calorimetry and microstructural analysis, and the effects of alloying elements and UV irradiation on the electrochemical corrosion behavior of bulk amorphous alloys were investigated. By the linear relationship between T_m and T_g, the amorphous formation capacity parameter T_rg=T_g/T_1 was rationally transformed into T_rg=. Kappa T_m/Tl+C/T_1, which reflects that the solid phase temperature T_m is also an important parameter affecting the amorphous formation ability, and also reveals the important role of the liquidus temperature Tt for the amorphous formation ability. On the other hand, the parameter T_rg is converted from the posterior parameter to the predictive parameter, which can be used to predict the alloy formation with higher amorphous formation ability. At the same time, this parameter reveals the influence of the solidification temperature range of the alloy on the amorphous forming ability of the alloy. According to this rule, a variety of three element Cu-Zr-Ti and Cu-Zr-Al bulk amorphous alloys have been designed and prepared. In this paper, the three element Cu-Zr-Ti bulk amorphous alloys have been designed and the Ti element content ranges from 7.5-8.5at.% to the bulk of the amorphous alloy. The crystalline alloy has large plasticity, and the Cu_ (54.5) Zr_ (37) Ti_8Ni_ (0.5), Cu_ (54.5) Zr_ (37) Ti_8Si_ (0.5), Cu_ (53.5) Zr_ (37) Ti_8Si_ (1.5)) of three kinds of amorphous alloy.Cu-Zr-Ti-Ni alloys are prepared by thermodynamic calculation and alloy solidification, and the alloy elements are added to the alloy. In addition, by analyzing the two element phase diagram between the components, Mo, Nb and Hf elements are selected to replace the Ti elements in Cu_ (50.2) Zr_ (40.8) Ti_9 block amorphous alloys, Cu_ (50.2) Zr_ (40.8) Ti_8Mo_ (1), Cu_ (50.2) Zr_ (40.8) (1) and 50.2) (40.8) (1) show the best plasticity and fracture in their respective systems. Strength. In all alloys designed in this paper, the compression plasticity and fracture strength of Cu_ (50) Zr_ (42.5) Ti_ (7.5), Cu_ (51.7) Zr_ (40.8) Ti_ (7.5), Cu_ (54.5) Zr_ (37) Ti_8Ni_ (0.5), Cu_ (50.2) Zr_ (40.8) Ti_8Nb_ (1) and 50.2) The indentation creep behavior of the two bulk amorphous matrix composites shows that the plasticity of the alloy is closely related to the structure of the amorphous matrix. Adding alloy elements Al, Ni, Si, Mo, Nb and Hf can improve the corrosion potential of the amorphous alloy of Cu-Zr-Ti block. On the other hand, the corrosion current density of Cu_ (54.5) Zr_ (37) Ti_8Si_ (0.5) alloys is obviously lower than that of Cu_. (55) Zr_ (37) Ti_8. was irradiated with ultraviolet light to study the electrochemical corrosion behavior of two Cu based bulk amorphous alloys. The dynamic polarization curves and electrochemical impedance spectroscopy showed that the corrosion current density (corrosion rate) and pitting resistance of Cu based bulk amorphous alloys were reduced and the resistance to pitting was increased under UV irradiation. The present Cu based bulk amorphous alloys have less pitting location and smaller pitting area under UV irradiation. It is proved that the Cu based bulk amorphous alloys have high resistance to pitting resistance in ultraviolet radiation.
【学位授予单位】：东南大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TG139.8
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本文编号：1926538