NiTi shape memory alloy cellular meshes: manufacturing by investment casting and characterization
NiTi shape memory alloy cellular meshes: manufacturing by investment casting and characterization
复制标题
NiTi 形状记忆合金蜂窝网：通过熔模铸造和表征制造
DOI：
10.1088/1361-665x/abadd1
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发表时间：
2020
影响因子：
4.1
通讯作者：
C. J. de Araújo
中科院分区：
文献类型：
--
作者：
E. O. S. Montenegro;E. Grassi;J. B. Simões;P. C. Sales da Silva;C. J. de Araújo
最近的研究表明，包括纯钛及其合金的常规网片可用于帮助人体各个部位（如面部、下颌、颅骨和膝盖）的骨折恢复。在这些应用程序和其他应用程序的预期提高效率，这项工作分析了一种类型的金属网，是与镍钛形状记忆合金（SMA），这是智能金属，表现出功能特性，如形状记忆效应（SME）和超弹性（SE）制造的热机械行为。开发具有不同单元设计、良好机械强度和可恢复变形的NiTi SMA补片，以取代钛补片并增强生物医学应用（以及其他领域的应用），可以被认为是当前的技术挑战。在此框架下，本研究旨在执行制造和机械特性的镍钛形状记忆合金网格的熔模铸造生产三种不同的细胞几何形状（圆形，六边形和正方形）在两种状态（铸造和热处理）。所获得的结果表明，制造的网格呈现功能特性，即使在铸态，热弹性相变和变形恢复的顺序为6%的证明。结果表明，在热处理和网格单元几何形状之间，后者是对网格力学行为影响最大的因素。一个简短的数值模拟的拉伸行为的网格是用来加深分析细胞的几何形状对它们的力学行为的影响。总体而言，具有圆形和方形单元的铸态补片在拉伸和弯曲条件下具有较高的刚度。所产生的网格显示出足够的热机械特性，以提高生物医学应用。这些结果支持传统的钛合金，不具有功能特性，与NiTi SMA的替代。
Recent studies have shown that conventional meshes comprising pure titanium and its alloys can be used to assist the recovery of bone fractures in various parts of the human body, such as the face, jaw, skull and knee. In anticipation of an improved efficiency for these applications and other applications, this work analyses the thermomechanical behaviour of a type of metallic mesh that is fabricated with NiTi shape memory alloys (SMAs), which are smart metals that exhibit functional properties, such as the shape memory effect (SME) and superelasticity (SE). The development of NiTi SMA meshes with different cell designs, good mechanical strength and recoverable deformation to replace titanium meshes and enhance biomedical applications (as well as applications in other fields) can be considered a current technological challenge. In this framework, this study aims to perform the fabrication and mechanical characterization of NiTi SMA meshes produced by investment casting with three different cell geometries (circular, hexagonal and square) in two states (as cast and heat treated). The obtained results show that the manufactured meshes present functional properties even in the as-cast state, as thermoelastic phase transformation and deformation recovery on the order of 6% is demonstrated. The results show that between the heat treatment and mesh cell geometry, the latter factor is the most influential factor in the mechanical behaviour of the meshes. A brief numerical simulation of the tensile behaviour of the meshes is used to deepen the analysis of the influence of cell geometry on their mechanical behaviour. Overall, as-cast meshes with circular and square cells present a high stiffness under tension and bending. The produced meshes show enough thermomechanical features to enhance biomedical applications. These results support the replacement of conventional titanium alloys, which do not possess functional properties, with NiTi SMAs.