Investigation on Morphology and Mechanical Properties of Rod Units in Lattice Structures Fabricated by Selective Laser Melting.

Chenchen Jing,Jiping Lu,Yanyan Zhu,Jie Wang,Changmeng Liu,Feifan Wang

doi:10.3390/ma14143994

Abstract

Selective laser melting (SLM) fabrication of lattice structures has attracted considerable interest due to its many immanent advantages, such as high specific strength. A wide variety of lattice structures have been designed and fabricated. However, as a vital prerequisite for design optimization, a clear relation between the process constraint of SLM and the apparent properties of the fabricated lattice structure has received much less attention. Therefore, this work systematically investigates the characterization and preformation of rod units, which are the basic components of lattice structures, so as to evaluate the SLM manufacturability of lattice structures. A series of rod units with different inclination angles and diameters were fabricated by SLM. Their morphology and mechanical properties were measured by scanning electron microscope observation and a tensile test, respectively. The inclination angle was found to have significant effects on profile error and little effect on mechanical properties. The higher the inclination angle, the larger the profile error. The characteristic diameter had no significant correlation with profile errors and mechanical properties. Based on systematic studies, a formula is proposed to evaluate the cross-sectional area of the fabricated rod units and further estimate their load capacity. This has important implications for optimizing the design of lattice structures fabricated by SLM.

Highlights

In a wide variety of engineering applications, such as in the aerospace, military, automotive, and medical industries, the weight of parts has significant impacts on both functional performance and usage cost [1,2,3,4]
The inclination angle and the diameter of the rod element have a limited influence on the mechanical properties of the rod, which implies that it is reasonable to use isotropic tensile strength value when designing the lattice structure
(3) The error fitting formula and cross-sectional area calculation formula of the rod units were proposed. The former can determine the longitudinal error according to the inclination angle

Summary

Introduction

In a wide variety of engineering applications, such as in the aerospace, military, automotive, and medical industries, the weight of parts has significant impacts on both functional performance and usage cost [1,2,3,4]. [14,15] These methods are complex, costly, have low material utilization efficiency [16], and it is difficult to fabricate very complicated lattice structures. This is where additive manufacturing, known as 3D printing, comes into play. The powder, fully melted by laser power, will combine with the previous layer and form a dense part [20,21,22,23] This method proposes an idea to fabricate complex lattice structures [24]. Al-Saedi et al [27] fabricated a functionally graded lattice structure by SLM, which has a higher energy absorption capacity than a uniform lattice structure

Methods

Results

Conclusion