Based on research done in this work, it seems that additive manufacturing processes are a valid way to produce internal features. Due to freedom of design, it is possible to make better and more effective constructs in parts where internal features are present. It is also possible to manufacture parts with equal structural properties to milled components of the same material. Laser additive manufacturing is still quite a new method for producing parts, compared to traditional milling; therefore it has time to evolve. Even if it does not replace traditional methods when making simple geometries due to its slow manufacturing speed, it can replace them when making complex internal features. Because optimisation of parameters in AM is crucial and the parameters are different to each material, the spectrum of material in use is quite narrow compared to traditional methods. Same materials like Ti64 and 316 steel kept appearing in different articles which also suggest this. More variety in materials can be expected as the time goes by and the process becomes more widely used.
The biggest downside of the process seems to be the manufacturing speed. The numbers used in this work are from a research quite old (2007) considering the age of the process.
The speeds are probably improved by now but specific values could not be found which suggest that it is either a secret or done by the manufacturer companies to themselves. The speed can be improved by adding more laser power but it is limited by the growth of the melt pool which worsens the quality of the part. That is why there seems to be a upper limit to manufacturing speeds.
It seems that many people are trying to improve current designs of applications with cooling channels. Number of patens filed in the field of additive manufacturing and cooling channel additive manufacturing in recent years also suggests this. Most of the patents seem to concentrate in the field of aerospace technology, mainly in turbine components and their cooling. Due to environmental issues this is only natural direction to go as more efficient engines mean less environmental load and people are trying to profit from it.
6.3 Value of this research and comparison to previous research
This research was made based on existing literature. Due to that it does not include a lot of scientifically new information. Even if key findings part of this work may provide new perspective to the topic, the novelty value of this research is quite low. Making work on this topic more valuable is discussed in the future research chapter.
6.4 Future research
The future research based on the subject could include manufacturing test pieces with internal channels as some actual research could greatly benefit the industry. Surface quality improving and self-supporting channel shape design should be important research topics as well as improving the processing times without reducing the quality of the finished part too much. Also different materials and their properties and processing parameters should be researched as the material range used in the articles seemed quite limited.
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