Benchmarking of dimensional accuracy and surface roughness for AlSi10Mg part by selective laser melting (SLM)

Author(s):  
K. Kamarudin ◽  
M. S. Wahab ◽  
A. A. Raus ◽  
Aqeel Ahmed ◽  
S. Shamsudin
Author(s):  
Mennatallah F El Kashouty ◽  
Allan EW Rennie ◽  
Mootaz Ghazy ◽  
Ahmed Abd El Aziz

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.


Materials ◽  
2018 ◽  
Vol 11 (3) ◽  
pp. 392 ◽  
Author(s):  
Xuesong Han ◽  
Haihong Zhu ◽  
Xiaojia Nie ◽  
Guoqing Wang ◽  
Xiaoyan Zeng

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2343 ◽  
Author(s):  
Ahmed Maamoun ◽  
Yi Xue ◽  
Mohamed Elbestawi ◽  
Stephen Veldhuis

Additive manufacturing (AM) of high-strength Al alloys promises to enhance the performance of critical components related to various aerospace and automotive applications. The key advantage of AM is its ability to generate lightweight, robust, and complex shapes. However, the characteristics of the as-built parts may represent an obstacle to the satisfaction of the parts’ quality requirements. The current study investigates the influence of selective laser melting (SLM) process parameters on the quality of parts fabricated from different Al alloys. A design of experiment (DOE) was used to analyze relative density, porosity, surface roughness, and dimensional accuracy according to the interaction effect between the SLM process parameters. The results show a range of energy densities and SLM process parameters for AlSi10Mg and Al6061 alloys needed to achieve “optimum” values for each performance characteristic. A process map was developed for each material by combining the optimized range of SLM process parameters for each characteristic to ensure good quality of the as-built parts. This study is also aimed at reducing the amount of post-processing needed according to the optimal processing window detected.


Author(s):  
Weipeng Duan ◽  
Meiping Wu ◽  
Jitai Han ◽  
Yiqing Ma ◽  
Peipei Lu ◽  
...  

A systematical work was studied to illustrate the influence of defocusing distance on the forming quality of inner structure fabricated by selective laser melting for Ti-6Al-4V alloy. The relationship between defocusing distance and dimensional accuracy, surface roughness as well as flatness was investigated, finite element analysis (FEA) was used to show the temperature distribution. The results show that defocusing distance not only had an impact on laser energy density, but also showed a significant influence on the surface pressure of the metal powder. Smaller defocusing distance (0.0 mm) accompanied with higher molten pool maximum temperature (3262.96°C), powder melting and splashing at the same time. On the contrary, larger defocusing distance leading to unmelted powder and powder bonding, which influences the forming quality of samples. Dimensional accuracy was less affected in 0.0, 1.0, 2.0 mm defocusing distance (5%), but changed dramatically when it is 3.0 mm (22%). In the same condition, similar variation trend of surface roughness (Ra) and flatness was observed, and varying from 5.1 to 27.3 μm and 0.05 to 0.26 mm, respectively. Simultaneously, the bottom surface is less affected, while the other three sides have the opposite situation. Pores and unmelted powder can be seen on the surface, it is the comprehensive effect of laser energy density and surface pressure. It proves that it is feasible to manufacture inner structure by controlling this process parameter during SLM process, the influence mechanism of defocusing distance on forming quality was also illustrated in this work.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Baopeng Zhang ◽  
Xuesong Han ◽  
Changpeng Chen ◽  
Wenqi Zhang ◽  
Hailong Liao ◽  
...  

Purpose The purpose of this study is to investigate the effect of the strut size and tilt angle on the densification behavior, surface roughness and dimensional accuracy of the selective laser melting AlSi10Mg lattice structure was investigated in this study. In this study, the characteristics such as the density, up-skin and down-skin roughness and dimensional accuracy of selective laser melting forming technology manufacturing (SLMed) AlSi10Mg cellular lattice structure were carried. This work reveals the effect of the strut size and tilt angle on the geometric characteristics of SLMed AlSi10Mg and is benefit for controlling the forming performance of the SLMed cellular lattice structure. Design/methodology/approach Based on AlSi10Mg powder, the influence of the tilt angle changed from 10° to 45° with an increment of 5° were investigated, the influence of the strut size was varied from 0.4 mm to 1.2 mm with an increment of 0.2 mm were investigated. The characteristics such as the density, up-skin and down-skin roughness, dimensional accuracy and mechanical properties of SLM-ed AlSi10Mg cellular lattice structure was carried. Findings Greater than 99% relative density can be achieved for different strut size when optimal process parameters are used. In the optimized process interval, the struts with a tilt angle of 10° can still be formed well, which is higher than the design limit of the inclined angle given in the related literature. The tilt angle has a significant effect on the surface roughness of the strut. The microhardness reached to 157 ± 3 HV, and the maximum compressive strength was 58.86 MPa, with the optimal process parameters. Originality/value In this study, the characteristics such as the density, up-skin and down-skin roughness and dimensional accuracy of SLMed AlSi10Mg cellular lattice structure were carried. With the optimal geometric parameters, the authors tested microhardness and compressive strength of the cellular lattice structure. The results of this study provide theoretical and experimental basis for the realization of high-quality manufacturing and optimization design of aluminum alloy cellular lattice structure, which will meet more diversified industrial needs.


Author(s):  
Filippo Simoni ◽  
Andrea Huxol ◽  
Franz-Josef Villmer

AbstractIn the last years, Additive Manufacturing, thanks to its capability of continuous improvements in performance and cost-efficiency, was able to partly replace and redefine well-established manufacturing processes. This research is based on the idea to achieve great cost and operational benefits especially in the field of tool making for injection molding by combining traditional and additive manufacturing in one process chain. Special attention is given to the surface quality in terms of surface roughness and its optimization directly in the Selective Laser Melting process. This article presents the possibility for a remelting process of the SLM parts as a way to optimize the surfaces of the produced parts. The influence of laser remelting on the surface roughness of the parts is analyzed while varying machine parameters like laser power and scan settings. Laser remelting with optimized parameter settings considerably improves the surface quality of SLM parts and is a great starting point for further post-processing techniques, which require a low initial value of surface roughness.


Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3603
Author(s):  
Tim Pasang ◽  
Benny Tavlovich ◽  
Omry Yannay ◽  
Ben Jakson ◽  
Mike Fry ◽  
...  

An investigation of mechanical properties of Ti6Al4V produced by additive manufacturing (AM) in the as-printed condition have been conducted and compared with wrought alloys. The AM samples were built by Selective Laser Melting (SLM) and Electron Beam Melting (EBM) in 0°, 45° and 90°—relative to horizontal direction. Similarly, the wrought samples were also cut and tested in the same directions relative to the plate rolling direction. The microstructures of the samples were significantly different on all samples. α′ martensite was observed on the SLM, acicular α on EBM and combination of both on the wrought alloy. EBM samples had higher surface roughness (Ra) compared with both SLM and wrought alloy. SLM samples were comparatively harder than wrought alloy and EBM. Tensile strength of the wrought alloy was higher in all directions except for 45°, where SLM samples showed higher strength than both EBM and wrought alloy on that direction. The ductility of the wrought alloy was consistently higher than both SLM and EBM indicated by clear necking feature on the wrought alloy samples. Dimples were observed on all fracture surfaces.


2019 ◽  
Vol 9 (9) ◽  
pp. 1922 ◽  
Author(s):  
Tae Woo Hwang ◽  
Young Yun Woo ◽  
Sang Wook Han ◽  
Young Hoon Moon

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.


2021 ◽  
Vol 15 ◽  
Author(s):  
Weishi Li ◽  
Kuanting Wang ◽  
Shiaofen Fang

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.


Sign in / Sign up

Export Citation Format

Share Document