Purpose

Nowadays, the PolyJet technique is used to fabricate low volume functional parts in engineering and biomedical applications. However, the mechanical properties of the components fabricated through this process are inferior in comparison to components fabricated through the traditional manufacturing process. This paper aims to attempt to investigate the influence of process parameters, i.e. raster angle, orientation and type of surface finish on mechanical properties of RGD840 material manufactured by the PolyJet process.

Design/methodology/approach

Initially, this study focuses on experimental evaluation of elastic modulus, ultimate tensile strength and percentage elongation of the material. Further detailed experimental study of true stress, true strain, and plastic strain are conducted. Computational analysis of plastic strain is performed by using finite element analysis (FEA) software ABAQUS. The value of strength coefficient (K) and strain hardening coefficient (n) is calculated by using the graphical method from the true stress-plastic strain curve.

Findings

It is observed that 90º raster angle, flat orientation and glossy surface are the best level of process parameters for the tensile strength, true stress and modules of elasticity of the RGD840 material and the obtained value are 27.88, 30.134 and 2891.5 MPa, respectively. The percentage elongation is maximum at 60º raster angle, flat orientation, and matte finish type and the obtained value is 23.38%. The optimum level of process parameters are 90° raster angle, Flat orientation, with Glossy surface finish. SEM analysis of the fracture surface of the tensile test specimen proves that the fracture surface is brittle in nature.

Originality/value

The novelty of this work lies in the fact that no attempts were made to investigate the computational investigation of mechanical properties of RGD840 material.

中文翻译：

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通过PolyJet工艺制造的RGD840材料的力学性能的实验和计算分析

目的

如今，PolyJet技术被用于制造工程和生物医学应用中的小批量功能部件。然而，与通过传统制造工艺制造的部件相比，通过该工艺制造的部件的机械性能较差。本文旨在尝试研究工艺参数（即光栅角度，取向和表面光洁度类型）对通过PolyJet工艺制造的RGD840材料的机械性能的影响。

设计/方法/方法

最初，这项研究着重于材料的弹性模量，极限抗拉强度和伸长率的实验评估。对真实应力，真实应变和塑性应变进行了更详细的实验研究。塑性应变的计算分析是通过使用有限元分析（FEA）软件ABAQUS进行的。强度系数（K）和应变硬化系数（n）的值是使用图形方法从真实的应力-塑性应变曲线中计算得出的。

发现

可以看出，对于RGD840材料的抗张强度，真实应力和弹性模量，最佳的工艺参数水平是90º光栅角，平坦取向和光滑表面，并且得到的值分别为27.88、30.134和2891.5 MPa。百分伸长率在60º光栅角，平面取向和无光饰面类型时最大，得出的值为23.38％。工艺参数的最佳水平是90°光栅角，平面取向和光滑的表面光洁度。拉伸测试样品的断裂表面的SEM分析证明该断裂表面本质上是脆性的。

创意/价值

这项工作的新颖性在于，没有尝试研究RGD840材料的机械性能的计算研究。