Laser Additive Manufacturing of Novel Aluminum Based Nanocomposite Parts: Tailored Forming of Multiple Materials

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Dongdong Gu ◽  
Hongqiao Wang ◽  
Donghua Dai
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Microstructural Evolution ◽  
Mechanical Performance ◽  
Laser Energy ◽  
Dimensional Accuracy ◽  
Ring Structure ◽  
Multiple Materials ◽  
Depth Relationship ◽  
Tailored Forming

The present study has proved the feasibility to produce the bulk-form TiC/AlSi10Mg nanocomposite parts with the novel reinforcing morphology and enhanced mechanical properties by selective laser melting (SLM) additive manufacturing (AM) process. The influence of linear laser energy density (η) on the microstructural evolution and mechanical performance (e.g., densification level, microhardness, wear and tribological properties) of the SLM-processed TiC/AlSi10Mg nanocomposite parts was comprehensively studied, in order to establish an in-depth relationship between SLM process, microstructures, and mechanical performance. It showed that the TiC reinforcement in the SLM-processed TiC/AlSi10Mg nanocomposites experienced an interesting microstructural evolution with the increase of the applied η. At an elevated η above 600 J/m, a novel regularly distributed ring structure of nanoscale TiC reinforcement was tailored in the matrix due to the unique metallurgical behavior of the molten pool induced by the operation of Marangoni flow. The near fully dense TiC/AlSi10Mg nanocomposite parts (>98.5% theoretical density (TD)) with the formation of ring-structured reinforcement demonstrated outstanding mechanical properties. The dimensional accuracy of SLM-processed parts well met the demand of industrial application with the shrinkage rates of 1.24%, 1.50%, and 1.72% in X, Y, and Z directions, respectively, with the increase of η to 800 J/m. A maximum microhardness of 184.7 HV0.1 was obtained for SLM-processed TiC/AlSi10Mg nanocomposites, showing more than 20% enhancement as compared with SLM-processed unreinforced AlSi10Mg part. The high densification response combined with novel reinforcement of SLM-processed TiC/AlSi10Mg nanocomposite parts also led to the considerably low coefficient of friction (COF) of 0.28 and wear rate of 2.73 × 10−5 mm3 · N−1 · m−1. The present work accordingly provides a fundamental understanding of the tailored forming of lightweight multiple nanocomposite materials system by laser AM.

Approximate Functionally Graded Materials for Multi-Material Additive Manufacturing

2018 ◽  
Author(s):  
Yuen-Shan Leung ◽  
Huachao Mao ◽  
Yong Chen
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Functionally Graded Materials ◽  
Functionally Graded ◽  
Gradual Transition ◽  
Material Distribution ◽  
Graded Materials ◽  
Base Materials ◽  
Multiple Materials ◽  
Am Processes

Functionally graded materials (FGM) possess superior properties of multiple materials due to the continuous transitions of these materials. Recent progresses in multi-material additive manufacturing (AM) processes enable the creation of arbitrary material composition, which significantly enlarges the manufacturing capability of FGMs. At the same time, the fabrication capability also introduces new challenges for the design of FGMs. A critical issue is to create the continuous material distribution under the fabrication constraints of multi-material AM processes. Using voxels to approximate gradient material distribution could be one plausible way for additive manufacturing. However, current FGM design methods are non-additive-manufacturing-oriented and unpredictable. For instance, some designs require a vast number of materials to achieve continuous transitions; however, the material choices that are available in a multi-material AM machine are rather limited. Other designs control the volume fraction of two materials to achieve gradual transition; however, such transition cannot be functionally guaranteed. To address these issues, we present a design and fabrication framework for FGMs that can efficiently and effectively generate printable and predictable FGM structures. We adopt a data-driven approach to approximate the behavior of FGM using two base materials. A digital material library is constructed with different combinations of the base materials, and their mechanical properties are extracted by Finite Element Analysis (FEA). The mechanical properties are then used for the conversion process between the FGM and the dual material structure such that similar behavior is guaranteed. An error diffusion algorithm is further developed to minimize the approximation error. Simulation results on four test cases show that our approach is robust and accurate, and the framework can successfully design and fabricate such FGM structures.

scholarly journals Characterisation of a High-Performance Al–Zn–Mg–Cu Alloy Designed for Wire Arc Additive Manufacturing

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1610 ◽  
Author(s):  
Paulo J. Morais ◽  
Bianca Gomes ◽  
Pedro Santos ◽  
Manuel Gomes ◽  
Rudolf Gradinger ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Additive Manufacturing ◽  
High Performance ◽  
Mechanical Performance ◽  
Fluorescence Analysis ◽  
Cold Metal Transfer ◽  
Direction Parallel ◽  
X Ray ◽  
Wire Arc Additive Manufacturing

Ever-increasing demands of industrial manufacturing regarding mechanical properties require the development of novel alloys designed towards the respective manufacturing process. Here, we consider wire arc additive manufacturing. To this end, Al alloys with additions of Zn, Mg and Cu have been designed considering the requirements of good mechanical properties and limited hot cracking susceptibility. The samples were produced using the cold metal transfer pulse advanced (CMT-PADV) technique, known for its ability to produce lower porosity parts with smaller grain size. After material simulations to determine the optimal heat treatment, the samples were solution heat treated, quenched and aged to enhance their mechanical performance. Chemical analysis, mechanical properties and microstructure evolution were evaluated using optical light microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray fluorescence analysis and X-ray radiography, as well as tensile, fatigue and hardness tests. The objective of this research was to evaluate in detail the mechanical properties and microstructure of the newly designed high-performance Al–Zn-based alloy before and after ageing heat treatment. The only defects found in the parts built under optimised conditions were small dispersed porosities, without any visible cracks or lack of fusion. Furthermore, the mechanical properties are superior to those of commercial 7xxx alloys and remarkably independent of the testing direction (parallel or perpendicular to the deposit beads). The presented analyses are very promising regarding additive manufacturing of high-strength aluminium alloys.

scholarly journals Additive Manufacturing of High-Entropy Alloys: A Review

Entropy ◽  
2018 ◽  
Vol 20 (12) ◽  
pp. 937 ◽  
Author(s):  
Shuying Chen ◽  
Yang Tong ◽  
Peter Liaw
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
High Efficiency ◽  
Mechanical Performance ◽  
Heating Temperature ◽  
Intermetallic Phase ◽  
Solid Solution Phase ◽  
High Entropy Alloys ◽  
Scanning Method ◽  
High Entropy

Owing to the reduced defects, low cost, and high efficiency, the additive manufacturing (AM) technique has attracted increasingly attention and has been applied in high-entropy alloys (HEAs) in recent years. It was found that AM-processed HEAs possess an optimized microstructure and improved mechanical properties. However, no report has been proposed to review the application of the AM method in preparing bulk HEAs. Hence, it is necessary to introduce AM-processed HEAs in terms of applications, microstructures, mechanical properties, and challenges to provide readers with fundamental understanding. Specifically, we reviewed (1) the application of AM methods in the fabrication of HEAs and (2) the post-heat treatment effect on the microstructural evolution and mechanical properties. Compared with the casting counterparts, AM-HEAs were found to have a superior yield strength and ductility as a consequence of the fine microstructure formed during the rapid solidification in the fabrication process. The post-treatment, such as high isostatic pressing (HIP), can further enhance their properties by removing the existing fabrication defects and residual stress in the AM-HEAs. Furthermore, the mechanical properties can be tuned by either reducing the pre-heating temperature to hinder the phase partitioning or modifying the composition of the HEA to stabilize the solid-solution phase or ductile intermetallic phase in AM materials. Moreover, the processing parameters, fabrication orientation, and scanning method can be optimized to further improve the mechanical performance of the as-built-HEAs.

scholarly journals Additive Manufacturing of Bone Scaffolds Using PolyJet and Stereolithography Techniques

2021 ◽  
Vol 11 (16) ◽  
pp. 7336
Author(s):  
Shummaila Rasheed ◽  
Waqas Akbar Lughmani ◽  
Muhannad Ahmed Obeidi ◽  
Dermot Brabazon ◽  
Inam Ul Ahad
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Dimensional Accuracy ◽  
Human Bone ◽  
Compression Tests ◽  
3D Scaffold ◽  
Bone Scaffolds ◽  
3D Printed ◽  
Printing Direction ◽  
Printing Techniques

In this study, the printing capability of two different additive manufacturing (3D printing) techniques, namely PolyJet and micro-stereolithography (µSLA), are investigated regarding the fabrication of bone scaffolds. The 3D-printed scaffold structures are used as supports in replacing and repairing fractured bone tissue. Printed bone scaffolds with complex structures produced using additive manufacturing technology can mimic the mechanical properties of natural human bone, providing lightweight structures with modifiable porosity levels. In this study, 3D scaffold structures are designed with different combinations of architectural parameters. The dimensional accuracy, permeability, and mechanical properties of complex 3D-printed scaffold structures are analyzed to compare the advantages and drawbacks associated with the two techniques. The fluid flow rates through the 3D-printed scaffold structures are measured and Darcy’s law is applied to calculate the experimentally measured permeability. The Kozeny–Carman equation is applied for theoretical calculation of permeability. Compression tests were performed on the printed samples to observe the effects of the printing techniques on the mechanical properties of the 3D-printed scaffold structures. The effect of the printing direction on the mechanical properties of the 3D-printed scaffold structures is also analyzed. The scaffold structures printed with the µSLA printer demonstrate higher permeability and mechanical properties as compared to those printed using the PolyJet technique. It is demonstrated that both the µSLA and PolyJet printing techniques can be used to print 3D scaffold structures with controlled porosity levels, providing permeability in a similar range to human bone.

scholarly journals Experimental and Computational Investigation of Lattice Sandwich Structures Constructed by Additive Manufacturing Technologies

2021 ◽  
Vol 5 (3) ◽  
pp. 95
Author(s):  
Nikolaos Kladovasilakis ◽  
Paschalis Charalampous ◽  
Konstantinos Tsongas ◽  
Ioannis Kostavelis ◽  
Dimitrios Tzetzis ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Mechanical Performance ◽  
Sandwich Structures ◽  
Volume Ratio ◽  
Dimensional Accuracy ◽  
High Porosity ◽  
Design Strategies ◽  
Fused Filament Fabrication ◽  
Geometrical Structures ◽  
Specific Distribution

Additive Manufacturing (AM) technologies offer the ability to construct complex geometrical structures in short manufacturing lead time coupled with a relatively low production cost when compared to traditional manufacturing processes. The next trend in mechanical engineering design is the adaption of design strategies that build products with lightweight lattice geometries like sandwich structures. These structures possess low mass, large surface area to volume ratio, high porosity, and adequate mechanical behavior, which are properties of great importance in scientific fields such as bioengineering, automotive, and aerospace engineering. The present work is focused on producing sandwich structures with complex lattice patterns like the Triply Periodic Minimal Surface (TPMS) Schwarz diamond structure. The specimens were manufactured with two different Additive Manufacturing procedures employing various relative densities. More specifically, Material Jetting Printing (MJP) and Fused Filament Fabrication (FFF) processes were employed to investigate the performance of Acrylonitrile Butadiene Styrene (ABS) lightweight lattice structures. These structures were examined using digital microscopy in order to measure the dimensional accuracy and the surface characteristics of the utilized AM technologies. Furthermore, three-point bending tests and finite elements analyses have been applied to investigate the mechanical performance of the proposed technologies and designs as well as the influence of the relative density on the Schwarz diamond TPMS structure. The experimental results demonstrate that the investigated structure possesses a remarkable performance in respect to its weight due to the specific distribution of its material in space.

scholarly journals Effects of Polypropylene Fibers on the Mechanical Performance of a 3D Printable Mix

2021 ◽  
Vol 10 (8) ◽  
pp. 43-46
Author(s):  
Ankit Pal ◽  
A.K. Jain
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Additive Manufacturing ◽  
Industrial Revolution ◽  
Mechanical Performance ◽  
Polypropylene Fibers ◽  
Construction Sector ◽  
Construction Work ◽  
Fourth Industrial Revolution ◽  
Manufacturing Technique

Application of automation in construction work has now become need of the hour. Automation in construction work can be done by implementing a technique known as additive manufacturing technique. Use of additive manufacturing in construction sector has the potential to bring fourth industrial revolution by using 3D concrete printers. This paper is based ona parametric experimental study to evaluate the effect of Polypropylene (PP) fibers on mechanical properties of a 3D printable concrete. PP fibers were used invaryingpercentage ratio of 0.02, 0.04, 0.08, 0.12 and 0.16 of binder at constant W/B ratio.

Additive Manufacturing of Continuous Carbon Fiber Reinforced Thermoplastic Composites: An Investigation on Process-Impregnation-Property Relationship

2020 ◽  
Author(s):  
Gongshuo Wang ◽  
Zhenyuan Jia ◽  
Fuji Wang ◽  
Chuanhe Dong ◽  
Bo Wu
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Carbon Fiber ◽  
Process Parameters ◽  
Mechanical Performance ◽  
Movement Speed ◽  
Fiber Reinforced ◽  
Influence Of Process Parameters ◽  
Continuous Carbon Fiber ◽  
Carbon Fiber Reinforced

Abstract Fused filament fabrication (FFF) is one of the most broadly used additive manufacturing technologies, which possesses the advantage of a reduction in fabrication time and cost for complex-structural parts. FFF-fabricated continuous carbon fiber reinforced thermoplastic (C-CFRTP) composites have seen their great potentials in the industry due to the extraordinary mechanical properties. However, the relationship among process parameters, impregnation percentage, and mechanical properties is still unknown, which has greatly hindered both the manufacturing and application of those advanced composite parts. For this reason, the influence of process parameters on the impregnation percentage and mechanical properties of C-CFRTP specimens has been investigated in this paper. The process-impregnation-properties relationship of FFF-fabricated C-CFRTP specimens has been revealed through theoretical analyses and experimental measurement. It could be concluded that the impregnation percentage served as the bridge connecting process parameters and mechanical properties, which would provide a great insight into the property improvement. The experimental results of microscopic measurement and mechanical tests indicated that the combination of low transverse movement speed, high nozzle temperature, and small layer thickness led to an improved impregnation percentage, which ultimately produced better mechanical properties. The findings in this work will guide the fabrication of C-CFRTP parts with excellent mechanical performance for practical engineering applications.

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