Institute Of Mechanics,Chinese Academy of Sciences
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Tribological behaviors of a Ni-free Zr-based bulk metallic glass in simulated physiological environments
No full textNi-free Zr-based bulk metallic glass (BMG) generally exhibits excellent combination of biocompatibility and mechanical properties, making it a potential candidate for biomedical implants. However, the in-vitro tribological behaviors and wear resistance of Zr-based BMGs still remain less understood. In this study, the wear process of a Ni-free biocompatible Zr60.14Cu22.31Al9.7Fe4.85Ag3 BMG in 3 simulated physiological environments, i. e., deionized (DI) water, 0.9 wt% NaCl solution, and phosphate buffer saline (PBS) solution, are studied using Si3N4 ceramic as the counter-material. The results indicate that Zr60.14Cu22.31Al9.7Fe4.85Ag3 BMG show a specific wear rate less than 1/3 of Ti6Al4V alloy in all the 3 simulated physiological environments, which also surpasses currently reported wear resistance of Zr-based BMGs in the same environments. Specifically, the wear process of Zr60.14Cu22.31Al9.7Fe4.85Ag3 BMG shows a 3-staged character, i.e., the running stage, the transition stage, and the dynamic stable stage, with the main wear mechanism transiting from adhesive wear to coexistence of adhesive wear and oxidative wear, and eventually to oxidative wear. During the transition of wear mechanism, the formation of oxide layer on the worn surface plays the key role, which provides protection against wear and leads to better wear resistance. Notably, the relatively higher wear rate of Zr60.14Cu22.31Al9.7Fe4.85Ag3 BMG in 0.9 wt% NaCl solution and PBS solution than that in DI water is attributed to the corrosivity of wear environments, which weakens the adhesion between oxide layer and BMG substrate thus promoting spalling of oxide layer and enhancing wear degradation. These results indicate the synergistic effect of corrosion and wear in Zr-based BMG in simulated physiological environments. Our work provides insights in developing wear-resistant Zr-based BMGs for implantable biomaterials
Tribological behaviors of a Ni-free Zr-based bulk metallic glass in simulated physiological environments
No full textNi-free Zr-based bulk metallic glass (BMG) generally exhibits excellent combination of biocompatibility and mechanical properties, making it a potential candidate for biomedical implants. However, the in-vitro tribological behaviors and wear resistance of Zr-based BMGs still remain less understood. In this study, the wear process of a Ni-free biocompatible Zr60.14Cu22.31Al9.7Fe4.85Ag3 BMG in 3 simulated physiological environments, i. e., deionized (DI) water, 0.9 wt% NaCl solution, and phosphate buffer saline (PBS) solution, are studied using Si3N4 ceramic as the counter-material. The results indicate that Zr60.14Cu22.31Al9.7Fe4.85Ag3 BMG show a specific wear rate less than 1/3 of Ti6Al4V alloy in all the 3 simulated physiological environments, which also surpasses currently reported wear resistance of Zr-based BMGs in the same environments. Specifically, the wear process of Zr60.14Cu22.31Al9.7Fe4.85Ag3 BMG shows a 3-staged character, i.e., the running stage, the transition stage, and the dynamic stable stage, with the main wear mechanism transiting from adhesive wear to coexistence of adhesive wear and oxidative wear, and eventually to oxidative wear. During the transition of wear mechanism, the formation of oxide layer on the worn surface plays the key role, which provides protection against wear and leads to better wear resistance. Notably, the relatively higher wear rate of Zr60.14Cu22.31Al9.7Fe4.85Ag3 BMG in 0.9 wt% NaCl solution and PBS solution than that in DI water is attributed to the corrosivity of wear environments, which weakens the adhesion between oxide layer and BMG substrate thus promoting spalling of oxide layer and enhancing wear degradation. These results indicate the synergistic effect of corrosion and wear in Zr-based BMG in simulated physiological environments. Our work provides insights in developing wear-resistant Zr-based BMGs for implantable biomaterials
一种竖向钻井台阵强震观测装置及其安装方法
No full text本申请涉及一种竖向钻井台阵强震观测装置及其安装方法，一种竖向钻井台阵强震观测装置，包括：设置在地表上的地震采集站、多级由井口垂直向下至井底设置的数字三分向地震加速度探头、连接在相邻的数字三分向地震加速度探头之间的级间连接筒组件和沿井深度设置于井内的注浆组件；相邻的数字三分向地震加速度探头和级间连接筒组件之间通过接头组件连接；各级数字三分向地震加速度探头电连接一起，地震采集站和第一级数字三分向地震加速度探头电连接。本申请所提供的一种竖向钻井台阵强震观测装置及其安装方法具有简化安装填注流程，消除管波干扰与方位角偏差，实现地震动从土层深处至地表传播的全程精细监测
一种聚能射流失稳判据与断裂时间的研究方法
No full text本发明提供了一种聚能射流失稳判据与断裂时间的研究方法, 其包括：1)首先，基于药型罩材料的应变硬化、应变率效应、热效应和颈缩效应，构建稳态时聚能射流的拉伸模型；2)在上述步骤1)完成的基础上叠加扰动构建扰动模型；3)通过对上述步骤2)构建的扰动模型求解来确定失稳判据和断裂时间。本发明构思合理，综合考虑了材料的应变硬化、应变率效应、热效应和颈缩效应的多种影响因素，通过对这些因素的深入分析，推导出了相应的失稳判据和断裂时间确定方法，能够更全面、精确地描述聚能射流的失稳行为和断裂过程，从而更有效地预测射流性能
柔性绕丝燃料组件轴流向流致振动实验装置及模拟方法
No full text本发明公开了一种柔性绕丝燃料组件模型轴流向流致振动实验装置及模拟方法，包括：波流水槽，用于存放实验用水，并能够产生波浪及水流，以使绕丝燃料组件模型发生流致振动；支撑架，设置有两个，分别安装于波流水槽的上游侧和下游侧；两个支撑架上均竖直安装有伸入波流水槽的立杆；绕丝燃料组件模型，一端通过万向联轴器与上游侧的立杆的下端连接，另一端通过钢丝绳与下游侧立杆的下端连接；钢丝绳的中部安装有用于给绕丝燃料组件模型施加轴向力的张紧器，以及用于监测张紧力大小的拉力传感器
一种基于有限元结果的多轴疲劳寿命矩阵化计算方法
No full text本发明公开了一种基于有限元结果的多轴疲劳寿命矩阵化计算方法，基于全局三维坐标轴对应的应力/应变张量，利用坐标变换和矩阵乘法计算斜面的三维坐标轴对应的应力/应变张量，将应力/应变张量中的正应力/应变数据和剪应力/应变数据进行分类；建立应力/应变存储数组、空间离散坐标变换数组和空间变换应力/应变数组；分别提取空间变换应变数组中的正应变数据和剪应变数据，计算所有节点对应的最大正应变幅值和最大剪应变幅值；基于最大正应变幅值和最大剪应变幅值，以及正应变临界面疲劳寿命计算公式以及剪应变临界面疲劳寿命计算公式，求解所有节点对应的疲劳寿命，本发明采用矩阵运算代替了传统算法中的循环、判断和标量代数运算
一种隧道锚固锚杆结构及施工方法
No full text本发明公开了一种隧道锚固锚杆结构及施工方法，多个骨节单元通过球铰结构顺次连接形成锚杆；在骨节单元上设置有第一贯穿孔、第二贯穿孔和第三贯穿孔；连接多个骨节单元的第二贯穿孔形成回风管路，连接多个骨节单元的第三贯穿孔形成进风管路；还包括多个牵引钢缆，牵引钢缆的顶部与锚杆最上部的骨节单元连接，钢缆穿过多个骨节单元的第一贯穿孔延伸至锚杆的底部的牵引钢缆的端部形成牵引控制端；通过多个牵引控制端的牵拉控制锚杆的角度弯曲。本发明提供的可控制弯曲的锚杆能够在施工过程中选择性的绕开软弱层将锚杆锚固在较为坚硬的地层，获得理想的锚杆与地层结构之间的摩擦力，提供更大的抗拉性能和锚固力，最终确保隧道安全和稳定性
