氘含量对Zr-4合金显微组织和力学性能的影响

发布时间：2018-01-12 17:24

本文关键词：氘含量对Zr-4合金显微组织和力学性能的影响　出处：《金属学报》2016年12期 　论文类型：期刊论文

【摘要】：采用XRD,OM,BSE,SEM和显微硬度计等手段研究了氘含量对Zr-4合金显微组织及力学性能的影响.结果表明,随着氘含量(质量分数)从1.35%增加到2.21%,氘化物数量增加,其形态及分布也发生了显著变化:在1.35%时,主要以晶内针状氘化物析出为主;随着氘含量增加,晶界块状氘化物快速增长;当氘含量进一步增加至2.21%时,晶界块状氘化物开始相互衔接,并逐渐向晶内生长.在氘含量较高的样品表层,有一定厚度的氘化物层形成,且层内出现微裂纹.所形成的氘化物以d-氘化物为主,而高氘含量样品表面有e-氘化物出现.样品心部至表面存在一定的硬度梯度,且随着氘含量的增加,样品的硬度增加,其相应的硬度梯度增大.随氘含量增加,样品的屈服强度略有增加,而抗压强度却显著下降,由1.35%下的1176 MPa降低到了2.21%下的856 MPa.抗压强度的降低与组织中微裂纹有关.样品压缩后的裂纹主要沿晶界块状氘化物形成并扩展,因此晶界块状氘化物是材料压缩性能下降的主要原因.
[Abstract]:The effect of deuterium content on the microstructure and mechanical properties of Zr-4 alloy was studied by means of SEM and microhardness tester. With the increase of deuterium content (mass fraction) from 1.35% to 2.21, the amount of deuteride increased and its morphology and distribution changed significantly: at 1.35. The main precipitation is acicular deuteride in crystal. With the increase of deuterium content, the grain boundary bulk deuteride increases rapidly. When the deuterium content is further increased to 2.21, the grain boundary deuterides begin to connect with each other and grow gradually into the crystal. A certain thickness of deuteride layer is formed in the surface layer of the sample with higher deuterium content. There are microcracks in the layer. The deuterides are mainly ddeuterides, while the edeuterides appear on the surface of the high deuterium content samples. There is a certain hardness gradient from the center of the sample to the surface, and with the increase of deuterium content. With the increase of deuterium content, the yield strength of the sample increased slightly, but the compressive strength decreased significantly. Down from 1, 176 MPa in 1.35% to 856 in 2.21%. The decrease of compressive strength is related to the microcrack in the microstructure. The crack formed and expanded along the grain boundary bulk deuteride after compression. Therefore, the grain boundary deuteride is the main reason for the decrease of the compression properties of the materials.
【作者单位】：北京科技大学新金属材料国家重点实验室;
【基金】：国家自然科学基金项目21171018和51271021资助~~
【分类号】：TG146.414
【正文快照】： 随着对能源需求的日益增加,核能的开发利用已成为世界各国尤其是中国发展新能源的重要途径之一[1,2].锆合金由于其较小的热中子吸收截面、优良的抗腐蚀性、热稳定性以及加工性能,广泛应用于核反应堆包壳及支架等结构材料[3,4].锆合金包壳目前所面临的主要问题是靠水侧的水汽腐

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