Purpose

Magnesium alloys are becoming prominent as an alternative to the permanent biomedical implants. In present work, electric discharge drilling (EDD) process has been investigated and optimized for ZM21 Mg alloy that can be used for producing perforated bone implants having geometrically precise micro holes.

Design/methodology/approach

Planning of experiments has been carried out in accordance to the Taguchi mixed L18 orthogonal array (OA). The hole overcut (HO), circularity at entrance (Cent) and circularity at exit (Cext) of drilled micro holes were measured as response characteristics during experimentation corresponding to different settings of EDD input parameters. For optimizing multiresponse characteristics, the hybrid approach of grey relational analysis, regression analysis and particle swarm optimization has been implemented.

Findings

It is found from hybrid approach that brass electrode along with Ip; 3 Amp, Ton; 50 µs and Toff; 52 µs outperformed over all other parametric settings against the collective result of response characteristics. The experimental values of response characteristics at suggested optimized setting are HO: 93.48 µm; Cent: 0.988 and Cext: 0.992, respectively.

Originality/value

The optimization of EDD process for developing perforated Mg alloy bone implants, using hybrid approach is still missing.

中文翻译：

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GRA-回归-PSO混合方法在镁合金放电微孔加工中的多特征优化

目的

镁合金作为永久性生物医学植入物的替代品正变得日益突出。在当前的工作中，已经对ZM21镁合金进行了放电钻孔（EDD）工艺的研究和优化，该工艺可用于生产具有几何精确微孔的穿孔骨植入物。

设计/方法/方法

根据田口混合L18正交阵列（OA）进行了实验计划。在实验过程中，测量了钻孔微孔（HO），入口处的圆度（Cent）和出口处的圆度（Cext）作为对应于EDD输入参数不同设置的响应特性。为了优化多响应特征，已经实现了灰色关联分析，回归分析和粒子群优化的混合方法。

发现

从混合方法中发现，黄铜电极与Ip一起存在。3安培，吨；50 µs和Toff；在响应特性的综合结果上，52 µs优于所有其他参数设置。在建议的最佳设置下，响应特性的实验值为HO：93.48 µm；分：0.988和分机：0.992。

创意/价值

使用混合方法开发多孔Mg合金骨植入物的EDD工艺的优化仍然缺乏。