CuZr基块体非晶复合材料的制备及其组织结构与性能的研究

发布时间：2018-01-09 20:18

本文关键词：CuZr基块体非晶复合材料的制备及其组织结构与性能的研究　出处：《南昌大学》2015年硕士论文　论文类型：学位论文

【摘要】：CuZr系块体非晶合金以其较低的成本、优良的非晶形成能力和力学性能受到国内外研究者们的广泛关注。且研究表明,在该合金系中如果存在B2-CuZr结晶相,合金的塑性将大大提高,并表现出明显“加工硬化”现象。因此,通过合理的微合金化,进一步提高CuZr合金系的非晶形成能力(GFA),形成大尺寸块体非晶合金,从而制备大块强韧非晶合金基复合材料,已成为非晶材料领域的研究热点。本文选取Cu47Zr47Al6合金系,通过加入微量元素Y,探究Y的添加对合金非晶形成能力、组织结构以及力学性能的影响;并选取实验条件下拥有最好非晶形成能力的合金系,分别通过冷轧及添加不同含量Nb和Ta,促进B2-CuZr增强相的生成,以期制备出具有优良综合力学性能的块体非晶基复合材料。选用纯度相对较低的原材料,利用真空铜模喷铸技术制备出名义成分为(Cu0.47Zr0.47Al0.06)100-xYx(x=0,2,4,6 at.%),φ=2 mm的棒状合金试样。通过X射线衍射仪、差示扫描量热仪、全自动压力试验机、金相显微镜、显微维氏硬度仪,分析Y的添加对合金非晶形成能力及力学性能的影响。结果表明:在一定量范围内,加入Y能明显提高Cu47Zr47Al6合金系的非晶形成能力,抑制B2-CuZr相的共析分解。在本实验范围内,Y加入量为4 at.%的试样玻璃形成能力(GFA)最好,抗压强度达到最大值1859 MPa。选取具有最好非晶形成能力的(Cu0.47Zr0.47Al0.06)96Y4成分,真空喷铸制备1.5mm×5 mm的板条状试样,通过冷轧促进结晶,探究形变对合金组织结构和力学性能的影响。结果表明:形变率为6.67%的预冷轧没有改变试样的结晶相组成,在铸态和轧后试样中,结晶相均为B2-CuZr、Cu10Zr7、CuZr2以及少量氧化物杂质相。但冷轧明显增加了试样中结晶相的含量。结晶相和残余应力的综合作用,使轧后试样硬度提高。在(Cu0.47Zr0.47Al0.06)96Y4合金的基础上分别添加不同含量的Nb、Ta元素,制备出名义成分为(Cu0.45Zr0.45Al0.06Y0.04)100-xNbx(x=0,1,2,3 at.%)、(Cu0.45Zr0.45Al0.06Y0.04)100-xTax(x=0,1,2,3 at.%),φ=2 mm的棒状合金试样,探讨Nb、Ta的加入对非晶合金组织及性能的影响。结果表明:Nb的添加降低了合金系的非晶形成能力,且Nb作为异质形核剂促进了B2-CuZr相的析出,改善了试样的力学性能。在本实验范围内,当Nb添加量为1 at.%时,试样内B2-CuZr相含量较多,表现为较好的室温塑性,塑性形变约为0.3%(±0.05%);一定量Ta的添加,可以降低(Cu0.47Zr0.47Al0.06)96Y4合金的非晶形成能力(GFA),促进单一B2-CuZr增强相的析出。在本实验范围内,Ta添加量为2 at.%时,在(Cu0.47Zr0.47Al0.06)96Y4块体非晶基体上可获得最高体积分数的B2-CuZr强韧相,表现出约为3%的最大塑性形变。
[Abstract]:CuZr bulk amorphous alloys have attracted much attention from researchers at home and abroad for their low cost, excellent amorphous forming ability and mechanical properties. If there is B2-CuZr crystalline phase in the alloy system, the plasticity of the alloy will be greatly improved, and the phenomenon of "work hardening" will be obvious. Therefore, reasonable microalloying is adopted. The amorphous forming ability of CuZr alloy system was further improved and large bulk amorphous alloy was formed, which resulted in the preparation of large bulk amorphous alloy matrix composites. In this paper, the Cu47Zr47Al6 alloy system is selected, and the addition of Y to the amorphous forming ability of the alloy is explored by adding the trace element Y. The influence of structure and mechanical properties; By cold rolling and adding different contents of NB and Ta, the formation of B2-CuZr reinforced phase was promoted by selecting the alloy system with the best amorphous forming ability under the experimental conditions. In order to prepare bulk amorphous matrix composites with excellent comprehensive mechanical properties, the raw materials with relatively low purity were selected. The nominal composition is Cu0.47Zr0.47Al0.06n 100-xYxOXYXYXYXYXYXUX 0OXYXYXUX OXYXYXYXUX (0) and 6T / 6AT.TECHANE). The specimens of 2mm rod alloy were tested by X-ray diffractometer, differential scanning calorimeter, automatic pressure tester, metallographic microscope and Vickers hardness tester. The effect of Y addition on the amorphous forming ability and mechanical properties of Cu47Zr47Al6 alloy was analyzed. The results showed that the addition of Y could obviously improve the amorphous forming ability of Cu47Zr47Al6 alloy system in a certain range. In the range of this experiment, the glass forming ability of the sample containing 4 at.% of Y is the best, which can inhibit the eutectoid decomposition of B2-CuZr phase. The compressive strength reached the maximum value of 1859 MPA. The composition of Cu0.47Zr0.47Al0.06 / 96Y4 with the best amorphous forming ability was selected. The strip specimen of 1.5mm 脳 5mm was prepared by vacuum spray casting, and the crystallization was promoted by cold rolling. The effect of deformation on the microstructure and mechanical properties of the alloy was investigated. The results showed that the pre-cold rolling with deformation rate of 6.67% did not change the crystalline phase composition of the sample, and it was found in the as-cast and post-rolled specimens. The crystalline phase is B2-CuZr-Cu10Zr7CuZr2 and a small amount of oxide impurity phase, but cold rolling obviously increases the content of crystalline phase and the comprehensive effect of crystalline phase and residual stress. The hardness of the samples was increased after rolling. Different contents of NB Ta were added on the basis of Cu0.47Zr0.47Al0.06Al-96Y4 alloy. The nominal composition is Cu0.45Zr0.45Al0.06Y0.04U 100-xNbxxnbxnxnxcnxcnbxxcnxxc0OOONBXXOXOXOXOXOXOXOXOXOX@@. Cu0.45Zr0.45Al0.06Y0.04n 100-xTaxxOOOXOXYOXYOXOXYOXYOXYOXYOXYLICOZHUS, 1, 1, 2, 2, 2, 2 mm Rod shape alloy samples, NB was studied in this paper. The effect of Ta addition on the microstructure and properties of amorphous alloys. The results show that the addition of 1% NB reduces the amorphous forming ability of the alloy system, and NB acts as a heterogeneous nucleating agent to promote the precipitation of B2-CuZr phase. The mechanical properties of the samples were improved. In the range of this experiment, the content of B2-CuZr phase was higher when NB content was 1 at.%, which showed good room temperature plasticity. The plastic deformation is about 0.3 (卤0.05). The amorphous forming ability of Cu0.47Zr0.47Al0.06Al-96Y4 alloy can be reduced by adding a certain amount of Ta. The precipitation of single B2-CuZr enhanced phase was promoted. In this experimental range, the addition of Ta was 2 at.%. The maximum volume fraction of B2-CuZr is obtained on Cu0.47Zr0.47Al0.06 / 96Y4 bulk amorphous matrix, showing the maximum plastic deformation of about 3%.
【学位授予单位】：南昌大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33

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