scholarly journals Technology fusion of metal injection moulding and selective laser melting for the manufacture of complex and multifunctional (hydraulic) components

2020 ◽  
Vol 4 (1) ◽  
pp. 1-8
Author(s):  
Martin Herold ◽  
Camilo Zopp ◽  
Oliver Neiske ◽  
Frank Schubert ◽  
Jan Hustert ◽  
...  

Selective laser melting (SLM) and metallic injection moulding (MIM) are established processes for the production of high-performance metallic components for small and large series. In the aerospace industry, where very high demands are placed on materials and components, both processes are still considered to be relatively new. In both processes, the conventional titanium alloy Ti-6Al-4V can be used in the form of powder. Currently, both technologies are only considered separately. By fusing components of the same type, multifunctional components with a high lightweight construction potential can be produced. In order to generate direct material fusion, the MIM component must be mechanically processed accordingly. In addition, suitable SLM process parameters must be developed in order to ensure both generative construction and high joint strength. To this end, a characterisation of the joining zone and the static joint strength was carried out. Furthermore, pressure test samples were designed and examined both statically and for fatigue strength. Thus, a high static joint strength could be proven. The compression test samples also withstood a fatigue strength of over 1 million cycles.

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1001
Author(s):  
Zongxian Song ◽  
Wenbin Gao ◽  
Dongpo Wang ◽  
Zhisheng Wu ◽  
Meifang Yan ◽  
...  

This study investigates the very-high-cycle fatigue (VHCF) behavior at elevated temperature (650 °C) of the Inconel 718 alloy fabricated by selective laser melting (SLM). The results are compared with those of the wrought alloy. Large columnar grain with a cellular structure in the grain interior and Laves/δ phases precipitated along the grain boundaries were exhibited in the SLM alloy, while fine equiaxed grains were present in the wrought alloy. The elevated temperature had a minor effect on the fatigue resistance in the regime below 108 cycles for the SLM alloy but significantly reduced the fatigue strength in the VHCF regime above 108 cycles. Both the SLM and wrought specimens exhibited similar fatigue resistance in the fatigue life regime of fewer than 107–108 cycles at elevated temperature, and the surface initiation mechanism was dominant in both alloys. In a VHCF regime above 107–108 cycles at elevated temperature, the wrought material exhibited slightly better fatigue resistance than the SLM alloy. All fatigue cracks are initiated from the internal defects or the microstructure discontinuities. The precipitation of Laves and δ phases is examined after fatigue tests at high temperatures, and the effect of microstructure on the formation and the propagation of the microstructural small cracks is also discussed.


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.


2019 ◽  
Vol 2019 (4) ◽  
pp. 392-397
Author(s):  
M. V. Gerov ◽  
E. Yu. Vladislavskaya ◽  
V. F. Terent’ev ◽  
D. V. Prosvirnin ◽  
O. S. Antonova ◽  
...  

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3910 ◽  
Author(s):  
Kashouty ◽  
Rennie ◽  
Ghazy

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.


2020 ◽  
Vol 10 (23) ◽  
pp. 8475
Author(s):  
Jan Patrick Sippel ◽  
Eberhard Kerscher

Understanding the mechanisms leading to very high cycle fatigue is necessary to make predictions about the behavior under various conditions and to ensure safe design over the whole lifetime of high-performance components. It is further vital for the development of possible measures to increase the very high cycle fatigue strength. This review therefore intends to give an overview of the properties of the fine granular area that have been observed so far. Furthermore, the existing models to describe the early crack initiation and crack growth within the very high cycle fatigue regime are outlined and the models are evaluated on the basis of the identified fine granular area properties. The aim is to provide an overview of the models that can already be considered refuted and to specify the respective open questions regarding the other individual models.


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