Selective Laser Melting of Curved Surface Metal Parts: A Fundamental Study on Surface Finish and Dimensional Accuracy

2019 ◽  
Author(s):  
Shrouq Alelaumi ◽  
Yue Zhou ◽  
Ali Khoshkhoo ◽  
Fuda Ning
Keyword(s):  
Selective Laser Melting ◽  
Surface Finish ◽  
Surface Texture ◽  
Dimensional Accuracy ◽  
Curved Surface ◽  
Stainless Steel 316L ◽  
Laser Melting ◽  
Fundamental Study ◽  
Surface Features ◽  
Metal Parts

Abstract Additive manufacturing (AM) of metal has been experiencing rapid growth in recent years by employing a variety of techniques. Among them, selective laser melting (SLM) of metal exhibits advantages in terms of its capabilities to build complex geometries, good surface finish, and high dimensional accuracy. Due to these benefits, SLM has demonstrated the ability to create metallic parts that can be applied in aerospace, automotive, and medical industries. However, most parts are geometrically complex with curved surface features, which would be difficult to be fabricated through traditional manufacturing methods. In order to increase the adoption and effectiveness of SLM for metal parts fabrication, the as-built surface finish and dimensional accuracy of the parts with curved surface features should be well understood. Great attempts have been made to investigate the surface texture of SLM as-built parts with various surface types. Most investigations characterize the surface texture of SLM-fabricated specimens with planar surface features. However, little is known about the surface finish and dimensional accuracy of SLM-fabricated metal parts with curved surfaces. Directly applying knowledge derived from planar surfaces to curved ones can be misleading. In this work, stainless steel 316L parts with curved surface features were built using SLM to examine the surface finish and dimensional accuracy. The results showed that 11 surface texture variables were significant at five different curvatures and the three most significant roughness variables were Sk, Spc, and Vmc. It was found that curvatures C1 and C5 significantly differed from the other curvatures (C2, C3, and C4) in all the 11 surface texture variables. In addition, the thickness of the as-built curved surface part at varied curvature locations would be almost constant.

scholarly journals Tool Life Performance of Injection Mould Tooling Fabricated by Selective Laser Melting for High-Volume Production

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3910 ◽  
Author(s):  
Kashouty ◽  
Rennie ◽  
Ghazy
Keyword(s):  
Selective Laser Melting ◽  
Injection Moulding ◽  
Dimensional Accuracy ◽  
High Volume ◽  
Operating Conditions ◽  
Composition Analysis ◽  
Stainless Steel 316L ◽  
Laser Melting ◽  
High Volume Production ◽  
Volume Production

Rapid Tooling processes are developing and proving to be a reliable method to compete with subtractive techniques for tool making. This paper investigates large volume production of components produced from Selective Laser Melting (SLM) fabricated injection moulding tool inserts. To date, other researchers have focused primarily on investigating the use of additive manufacturing technology for injection moulding for low-volume component production rather than high volume production. In this study, SLM technology has been used to fabricate four Stainless Steel 316L tool inserts of a similar geometry for an after-market automotive spare part. The SLM tool inserts have been evaluated to analyse the maximum number of successful injections and quality of performance. Microstructure inspection and chemical composition analysis have been investigated. Performance tests were conducted for the four tool inserts before and after injection moulding in the context of hardness testing and dimensional accuracy. For the first reported time, 150,000 injected products were successfully produced from the four SLM tool inserts. Tool inserts performance was monitored under actual operating conditions considering high-level demands. In the scope of this research, SLM proved to be a dependable manufacturing technique for most part geometries and an effective alternative to subtractive manufacturing for high-volume injection moulding tools for the aftermarket automotive sector.

Build Orientation Effect on Geometric Performance of Curved-Surface 316L Stainless Steel Parts Fabricated by Selective Laser Melting

2020 ◽  
Vol 142 (12) ◽  
Author(s):  
Yue Zhou ◽  
Fuda Ning
Keyword(s):  
Stainless Steel ◽  
Selective Laser Melting ◽  
316L Stainless Steel ◽  
Curved Surface ◽  
Laser Melting ◽  
Metal Parts ◽  
Build Orientation ◽  
Practical Engineering ◽  
Actual Profile ◽  
Surface Metal

Abstract Selective laser melting (SLM) is a powder bed fusion additive manufacturing technology that allows the production of high-performance metal parts with geometrically complex shapes, such as curved surface, can be used in practical engineering applications. In recent years, systematic attempts have been made to uncover the material-process-microstructure-property linkage in SLM-fabricated planar-surface metal parts; however, little is known on the performance and quality of SLM-fabricated metal parts with curved surfaces. In this paper, we studied the effects of build orientation on the geometric performance of SLM-built 316L stainless steel (SS) samples with a sinusoidal curved surface. The results indicated that the average values of profile roughness Ra and surface texture attributes Sa, Sk, and Vmc decreased with the increase in build orientation. Moreover, the locations at curvatures C2 and C4 exhibited the best surface finish at the build orientation of 75 deg and 90 deg. In addition, the least square method was used to fit the actual profile of the curved surface of as-built samples fabricated at each build orientation, and it was found the actual profile demonstrated the best consistency with the designed one at 90 deg build orientation. In this paper, the process–curvature–geometric performance relationship of SLM-built metal parts with curved surface was uncovered. In addition, this paper provides keen insights into assessing the geometric performance of SLM-built curved-surface metal parts and establishes a roadmap toward SLM-fabrication of metal parts with complex geometries for practical engineering applications.

scholarly journals Fabrication of Mesh Patterns Using a Selective Laser-Melting Process

2019 ◽  
Vol 9 (9) ◽  
pp. 1922 ◽  
Author(s):  
Tae Woo Hwang ◽  
Young Yun Woo ◽  
Sang Wook Han ◽  
Young Hoon Moon
Keyword(s):  
Selective Laser Melting ◽  
Laser Scanning ◽  
Dimensional Accuracy ◽  
Base Plate ◽  
Steel Powder ◽  
Melting Process ◽  
304 Stainless Steel ◽  
Process Conditions ◽  
Laser Melting ◽  
Metal Mesh

The selective laser-melting (SLM) process can be applied to the additive building of complex metal parts using melting metal powder with laser scanning. A metal mesh is a common type of metal screen consisting of parallel rows and intersecting columns. It is widely used in the agricultural, industrial, transportation, and machine protection sectors. This study investigated the fabrication of parts containing a mesh pattern from the SLM of AISI 304 stainless steel powder. The formation of a mesh pattern has a strong potential to increase the functionality and cost-effectiveness of the SLM process. To fabricate a single-layered thin mesh pattern, laser layering has been conducted on a copper base plate. The high thermal conductivity of copper allows heat to pass through it quickly, and prevents the adhesion of a thin laser-melted layer. The effects of the process conditions such as the laser scan speed and scanning path on the size and dimensional accuracy of the fabricated mesh patterns were characterized. As the analysis results indicate, a part with a mesh pattern was successfully obtained, and the application of the proposed method was shown to be feasible with a high degree of reliability.

Physical properties and microstructure study of stainless steel 316L alloy fabricated by selective laser melting

2017 ◽  
Author(s):  
Nurul Kamariah Md Saiful Islam ◽  
Wan Sharuzi Wan Harun ◽  
Saiful Anwar Che Ghani ◽  
Mohd Asnawi Omar ◽  
Mohd Hazlen Ramli ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Physical Properties ◽  
Selective Laser Melting ◽  
Stainless Steel 316L ◽  
Laser Melting

scholarly journals Selective laser melting for improving quality characteristics of a prism shaped topology injection mould tool insert for the automotive industry

2021 ◽  
pp. 095440622198938
Author(s):  
Mennatallah F El Kashouty ◽  
Allan EW Rennie ◽  
Mootaz Ghazy ◽  
Ahmed Abd El Aziz
Keyword(s):  
Surface Roughness ◽  
Selective Laser Melting ◽  
Automotive Industry ◽  
Injection Moulding ◽  
Dimensional Accuracy ◽  
Quality Characteristics ◽  
Surface Topology ◽  
Laser Melting ◽  
Injection Mould ◽  
Tool Insert

Manufacturing process constraints and design complexities are the main challenges that face the aftermarket automotive industry. For that reason, recently, selective laser melting (SLM) is being recognised as a viable approach in the fabrication of injection moulding tool inserts. Due to its versatility, SLM technology is capable of producing freeform designs. For the first reported time, in this study SLM is recognized for its novel application in overcoming fabrication complexities for prism shaped topology of a vehicle headlamp’s reflector injection moulding tool insert. Henceforth, performance measures of the SLM-fabricated injection mould tool insert is assessed in comparison to a CNC-milled counterpart to improve quality characteristics. Tests executed and detailed in this paper are divided into two stages; the first stage assesses both fabricated tool inserts in terms of manufacturability; the second stage assesses the functionality of the end-products by measuring the surface roughness, dimensional accuracy and light reflectivity from the vehicle reflectors. The results obtained show that employing SLM technology can offer an effective and efficient alternative to subtractive manufacturing, successfully producing tool inserts with complex surface topology. Significant benefits in terms of surface roughness, dimensional accuracy and product functionality were achieved through the use of SLM technology. it was concluded that the SLM-fabricated inserts products proved to have relatively lower values of surface roughness in comparison to their CNC counterparts.

Benchmark test artifacts for selective laser melting – a critical review

2021 ◽  
Vol 15 ◽  
Author(s):  
Weishi Li ◽  
Kuanting Wang ◽  
Shiaofen Fang
Keyword(s):  
Selective Laser Melting ◽  
High Surface ◽  
Dimensional Accuracy ◽  
Melting Process ◽  
Design Guidelines ◽  
Laser Melting ◽  
Specific Test ◽  
Benchmark Test ◽  
High Surface Quality ◽  
Machine Performance

Background: Selective laser melting is the best-established additive manufacturing technology for high-quality metal part manufacturing. However, the widespread acceptance of the technology is still underachieved, especially in critical applications, due to the absence of a thorough understanding of the technology, although several benchmark test artifacts have been developed to characterize the performance of selective laser melting machines. Objective: The objective of this paper is to inspire new designs of benchmark test artifacts to understand the selective laser melting process better and promote the acceptance of the selective laser melting technology. Method: The existing benchmark test artifacts for selective laser melting are analyzed comparatively, and the design guidelines are discussed. Results: The modular approach should still be adopted in designing new benchmark test artifacts in the future, and task-specific test artifacts may also need to be considered further to validate the machine performance for critical applications. The inclusion of the design model in the manufactured artifact, instead of the conformance to the design specifications, should be evaluated after the artifact is measured for the applications requiring high-dimensional accuracy and high surface quality. Conclusion: The benchmark test artifact for selective laser melting is still under development, and a breakthrough of the measuring technology for internal and/or inaccessible features will be beneficial for understanding the technology.

In Implementing a Metal 3D AM Machine

2018 ◽  
Vol 786 ◽  
pp. 356-363
Author(s):  
Tero Jokelainen ◽  
Kimmo Mäkelä ◽  
Aappo Mustakangas ◽  
Jari Mäkelä ◽  
Kari Mäntyjärvi
Keyword(s):  
Additive Manufacturing ◽  
Selective Laser Melting ◽  
Dimensional Accuracy ◽  
Acceptance Test ◽  
Aisi 316L ◽  
Laser Melting ◽  
Geometrical Accuracy ◽  
Machine Performance ◽  
Geometrical Features ◽  
Made In

Additive Manufacturing (AM) does not yet have a standardized way to measure performance. Here a AM machines dimensional accuracy is measured trough acceptance test (AT) and AM machines capability is tested trough test parts. Test parts are created with specific geometrical features using a 3D AM machine. Performance of the machine is then evaluated trough accuracy of test parts geometry. AM machine here uses selective laser melting (SLM) process. This machine has done Factory acceptance test (FAT) to ascertain this machine ́s geometrical accuracy with material AISI 316L. Manufacturer promises accuracy of ±0.05 mm. These parts are used as comparison to AT parts made in this study. After installation two AT parts are manufactured with AM machine. One with AISI 316L and one AlSi10Mg. Dimensional accuracy of geometrical features on these parts are then compared to FAT part and to one another. Machines capability is measured trough two test parts done with material AlSi10Mg. Two of the test parts are done at the same time using same model as the FAT. Parts are printed without supports and with features facing same directions. Features of these parts were then evaluated. Another test to find out AM machines capability was to create part consisting of pipes doing 90˚ angle resulting in horizontal and vertical holes. Dimensional accuracy and circularity of holes was measured. Through these tests machines capability is benchmarked.

scholarly journals Investigation on Selective Laser Melting AlSi10Mg Cellular Lattice Strut: Molten Pool Morphology, Surface Roughness and Dimensional Accuracy

Materials ◽  
2018 ◽  
Vol 11 (3) ◽  
pp. 392 ◽  
Author(s):  
Xuesong Han ◽  
Haihong Zhu ◽  
Xiaojia Nie ◽  
Guoqing Wang ◽  
Xiaoyan Zeng
Keyword(s):  
Surface Roughness ◽  
Selective Laser Melting ◽  
Molten Pool ◽  
Dimensional Accuracy ◽  
Laser Melting
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