State-of-the-Art Essay On Additive Manufacturing Compared With Subtractive Manufacturing.

You will be required to produce a state-of-the-art literature survey on the topic of Additive Manufacturing compared with Subtractive Manufacturing processes. In this report you will examine a very brief historical context of both technologies, before exploring the similarities and differences in each technology. Attention should be paid to the digital interface of each technology, drawing upon the elements discussed in both the lecture and practical sessions. Your report should include but not be limited to discussions of

• The relevance of part digitisation and it implications on the design and evaluation process
• Limitations on what can and cannot be realised by design
• Manufacturing similarities and constraints
• Material processing capabilities
• Manufacturing complexity and ease of use
• Variations of technological platforms
• Performance based metrics – Resolution, quality, production time, multiplexing, etc

Comparison of Additive and Subtractive Manufacturing Processes

This report is going to discuss about the traditional manufacturing process and additive manufacturing process. Traditional manufacturing process is a process that follows the protocol while producing the products that they will keep backup products for emergency purposes (Vaezi, Seitz and Yang  2013). Whereas additive manufacturing is the process that uses digital 3D, design to create any component, by depositing them into layers. Additive manufacturing has emerged with new manufacturing protocols, so that they can replace traditional process for manufacturing. The report will further discuss about the implications of additive and traditional manufacturing processes in the market. The evaluation process and the design of the processes sand the working of the manufacturing processes will be discussed (Huang et al. 2013). The report will discuss about the limitations of using this manufacturing techniques. Both the manufacturing process has some similarity and some differences, in spite of the technologies involved in it. The capabilities of the manufacturing process to prepare the products within the given period. It is believed that one day additive manufacturing will replace the subtractive manufacturing completely in the rising companies. Future implementations and betterment for the additive manufacturing processes are discussed in  the later part of the report. This will help the additive manufacturing process to enhance their flexibility and will develop in a huge way. But few peoples are there , who thinks that both the manufacturing techniques are needed in the industries.

Traditional manufacturing process is also known as subtractive manufacturing. Traditional manufacturing process does not have any certain disadvantages, with time all the problems has been solved. This manufacturing process uses CNC machining; this means that the process involves removal of large piece of materials with the help of standard machining process. The process includes milling, drilling or turning and this is being done until the prototype for the process is being created. There are different processes of manufacturing. Processes like injection and forming are used for large-scale manufacturing. On the other hand, 3D printing is used for small projects, so that it can help economically. Given below is a chart that compares the cost that is involved in manufacturing GoPro through injection as compared with selective laser sintering.

Fig1: Cost of GoPro

(Source: Lee, An and Chua 2017)

The traditional manufacturing process requires time to prepare a product and launch it to the companies. The time taken to produce the first module will be 15- 60 days. But in case of 3D printing , he printing is done on the basis of the demand and are delivered according to this. In this there is no need of tooling. Moreover , subtractive manufacturing gives the opportunity to develop , design , manufacture and prototype in the materials of end users. The subtractive prototyping model works with metals including Acetal Coplymer , ABS and many more. This typically depends on the design of the application , the materials can be chosen on the basis of their flexibility , strength , chemical resistance and other factors.

Advantages and Limitations of Traditional Manufacturing Process

Fig2: Steps involved in traditional manufacturing process

(Source: MacDonald and Wicker 2016)

There is a huge advantage of using subtractive manufacturing. This avoids layering of materials , thus the product manufactured offers a variety of surface. As this process involves removing of materials instead of adding them , gives a good dimensional control. The limitation of subtractive manufacturing process is that  sometimes it leads to waste of some materials and due to geometric limitations it is hard to handle at some places. Examples of subtractive manufacturing processes are:

MDX-15 MDX-20: These machines are used for small objects and jewelry by using benchtop prototyping. This supports the precision models as this can be fitted in desktop and mill – tooling board. The model functions at featuring the milling at a resolution of 0.001 and scanning with a resolution of 0.002.

Fig3: MDX-15 MDX-20

(Source: Huang et al. 2015)

MDX-4A : This is a subtractive rapid prototyping system , without any rotary axis and with a large 12 in. x12 in.x 4.1in.       

Fig4: MDX-4A

(Source: Huang et al. 2015)

 Parts manufactured quality: Traditional manufacture was discovered 30 years ago, thus this is the mature and reliable form of manufacturing. The products delivered with this manufacturing process are that the product produced is complete and there is no chances of having inaccuracies (Kalpakjian, Vijai Sekar and Schmid 2014).

Wide range of materials: This manufacturing process offers a wide range of product. Thus the design made are unique as there are huge number of materials available.

Additive manufacturing is a procedure in which 3D digital design is used to construct a module in layers by adding up materials.  Different types of plastics, metals and composite materials are being used for this manufacturing process (Thompson et al. 2016). 3D printing is a synonym used for additive manufacturing process. There are several different additive manufacturing process, this are as follows:

• Creativity Comes Next
• VAT Photopolymerization
• Powder Bed Fusion
• Binder Jetting (3D Printing)
• Material Jetting
• Sheet Lamination

The working of additive manufacturing is, they add the materials to the process rather than producing a result for the manufacturing. Additive manufacturing process creates a structure by adding up thousands of layers to create a product. This process is done with the help of special CDA software and a computer. This can communicate messages for the printer, so the printed material is in the desired shape. This is useful when used with a huge range of different materials, the printer is asked to print the same substance repeatedly forming a wafer thin layer at a time (Hopkinson and Dicknes 2013). These are repeated until the shape gets completed.

 The shapes produced with the additive technology are high level. This gives a variety of shapes produced. Designs that can be easily mould into one shape can be achieved with the help of this manufacturing. Moreover, the manufactured product achieved is stronger than the product delivered with traditional way of manufacturing. The process is completed within a short period (Wong and Hernandez 2014). The implementation of this technology had driven the production to higher rates. The types of additive manufacturing are :

Additive Manufacturing: Working Mechanisms and Processes

3D Printing:  This is basically referred to the process of fabrication of objects by depositing materials with the help of a printer technology. This is different from additive manufacturing process in some aspects.

Rapid prototyping: Rapid prototyping is used for creating a functional component in addition to creating a test design.

Selective laser sintering: These is the most common technique used in additive manufacturing process. This process includes merging the particles of the materials

Fig5: Image of SLS

(Source: Huang et al. 2015)

Unlimited designs: Additive manufacturing offers huge range different designs. Moreover, with the help of this manufacturing process the complexes designs can be done and also allows the production of incorporated components (Bell et al 2015). This is very much important in manufacturing as this helps in developing new designs. This manufacturing process is said to be complexity free , as the design does not impact on the cost of the manufacturing.

Flexible supply chains: For producing the products, there is no need of any special tooling or casting. Therefore moving the production to a different component is achieved easily without any problem (Song et al. 2015).  There is no need of extra cost for redesigning the model or stages of the products, the cost of production does not gets influenced by this for both low volume work or for prototyping (Cooper  2014). This is very much useful for developing the product for highly productive market.

Product development: As there is no need of tooling or casting the design produced by additive manufacturing, the manufacturing is done within a short period with keeping in mind the cost. Thus, the product prepared is cost effective.   

1. High production cost: As the techniques used in the manufacturing process is high, thus the production rate becomes higher. Lot of time is required for advancing the features.
   
   
2. Production process is discontinuous: For maintaining the economy, only one part is launched at a time. Thus, the production occurs is discontinuous (Scheck et al. 2016).
   
   
3. Post processing is required for additive manufacturing: Additive manufacturing process gives low finishing product surface and low accuracy than the other manufacturing processes.
   
   
4. Vast knowledge is required for design and setting up the application: The designer needs to have a good knowledge about the application developing.
   
   
5. Defects can arise due to layering and multiple interfaces: Sometimes defect arises as it is done with adding up multiple layers.

After combining both the technologies, the drawbacks of the Additive manufacturing can be removed. The accuracy for dimensional and geometrical can be improved. In addition to this, the surface finishing can be improved. This all features can be improved with the help of sanding, abrasive blasting, machining and coating. To enhance the mechanical properties and surface quality, resin infiltration or electroplating can be done (Baumers et al. 2016). It is expected that within 10 years, AM technologies is going to change the way of manufacturing. With enhancement in the requirements, the additive manufacture can gain huge popularity as all the new developing companies will incorporate this technology in them. The flexibility will be increased as their will be evolution in the supply chain management. Moreover, there will be a new concept introduced that will manufacture only the demanded part.

Additive and traditional manufacturing process has huge important in the industry. Both have equal importance in the market. However, their lies some differences between both the manufacturing processes. Differences between additive and traditional manufacturing processes are as follows:

1. There are unlimited designs for additive manufacturing process. The processes developed irrespective of the complexity of design (Conner et al 2015). Whereas the complexity in design can’t be handled with the traditional process.
   
   
2. Huge range of material is offered in the case of traditional manufacturing process whereas additive manufacturing process offers fewer materials.
   
   
3. The time required in processing the product is less as there is no need of tooling casting in case of the additive manufacturing. On the other hand, traditional manufacturing involves more time.
4. Additive manufacturing is cost effective process as there is no need of tooling and casting.
   
   
5. The product developed with the traditional way of manufacturing is complete and accurate, but the product prepared with additive manufacturing has some inaccuracies in it (Kruth, Leu and Nakagawa 2013).
   
   
6. Production rate of additive manufacturing process becomes higher as compared to traditional manufacturing process. This increases as the implementation of additional layer takes place in this manufacturing process.
   
   
7. High skilled and knowledgeable employees are required to design the applications in additive manufacturing process whereas no such requirement is needed for the employees working with traditional manufacturing process. Knowledgeable person only can handle the designing and they require deep knowledge , so they can come up with new design every time ( Turner, Strong and Gold 2014).

Conclusion

From the above report, it can be concluded that, both the manufacturing process has some significant features. This significant features, helps them to manufacture the products as needed. From the above report, it is observed that traditional way of manufacturing uses more materials and requires more timing for manufacturing the products as compared to that of additive manufacturing. The additive manufacturing can easily resolve the complexity and can easily design the complex products. The products are divided into layers, and the layers are added and form a structure. Further, the report discusses about the advantages and disadvantages of traditional and additive manufacturing. Types of traditional and additive manufacturing are discussed in the later part of the report. In addition, the future scope for additive manufacturing is discussed in the report. Comparison is made between both the manufacturing processes that are the additive manufacturing process and the traditional manufacturing. Therefore, it can be concluded that both the technologies are equally important for manufacturing processes.

References

Baumers, M., Dickens, P., Tuck, C. and Hague, R., 2016. The cost of additive manufacturing: machine productivity, economies of scale and technology-push. Technological forecasting and social change, 102, pp.193-201.

Bell, I.R., Sarter, B., Standish, L.J., Banerji, P. and Banerji, P., 2015. Low doses of traditional nanophytomedicines for clinical treatment: manufacturing processes and nonlinear response patterns. Journal of nanoscience and nanotechnology, 15(6), pp.4021-4038.

Conner, B.P., Manogharan, G.P., Martof, A.N., Rodomsky, L.M., Rodomsky, C.M., Jordan, D.C. and Limperos, J.W., 2014. Making sense of 3-D printing: Creating a map of additive manufacturing products and services. Additive Manufacturing, 1, pp.64-76.

Cooper, K.G., 2014. Rapid prototyping technology (Vol. 200). New York, NY: Marcel Dekker.

Hopkinson, N. and Dicknes, P., 2013. Analysis of rapid manufacturing—using layer manufacturing processes for production. Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 217(1), pp.31-39.

Huang, S.H., Liu, P., Mokasdar, A. and Hou, L., 2013. Additive manufacturing and its societal impact: a literature review. The International Journal of Advanced Manufacturing Technology, 67(5-8), pp.1191-1203.

Huang, Y., Leu, M.C., Mazumder, J. and Donmez, A., 2015. Additive manufacturing: current state, future potential, gaps and needs, and recommendations. Journal of Manufacturing Science and Engineering, 137(1), p.014001.

Kalpakjian, S., Vijai Sekar, K.S. and Schmid, S.R., 2014. Manufacturing engineering and technology. Pearson.

Kruth, J.P., Leu, M.C. and Nakagawa, T., 2013. Progress in additive manufacturing and rapid prototyping. Cirp Annals, 47(2), pp.525-540.

Lee, J.Y., An, J. and Chua, C.K., 2017. Fundamentals and applications of 3D printing for novel materials. Applied Materials Today, 7, pp.120-133.

MacDonald, E. and Wicker, R., 2016. Multiprocess 3D printing for increasing component functionality. Science, 353(6307), p.aaf2093.

2014. Turner, B., Strong, R. and A. Gold, S., 2014. A review of melt extrusion additive manufacturing processes: I. Process design and modeling. Rapid Prototyping Journal, 20(3), pp.192-204.

Scheck, C.E., Wolk, J.N., Frazier, W.E., Mahoney, B.T., Morris, K., Kestler, R. and Bagchi, A., 2016. Naval additive manufacturing: improving rapid response to the warfighter. Naval Engineers Journal, 128(1), pp.71-75.

Song, B., Zhao, X., Li, S., Han, C., Wei, Q., Wen, S., Liu, J. and Shi, Y., 2015. Differences in microstructure and properties between selective laser melting and traditional manufacturing for fabrication of metal parts: A review. Frontiers of Mechanical Engineering, 10(2), pp.111-125.

Thompson, S.M., Bian, L., Shamsaei, N. and Yadollahi, A., 2015. An overview of Direct Laser Deposition for additive manufacturing; Part I: Transport phenomena, modeling and diagnostics. Additive Manufacturing, 8, pp.36-62.

Vaezi, M., Seitz, H. and Yang, S., 2013. A review on 3D micro-additive manufacturing technologies. The International Journal of Advanced Manufacturing Technology, 67(5-8), pp.1721-1754.

Wong, K.V. and Hernandez, A., 2014. A review of additive manufacturing. ISRN Mechanical Engineering, 2012.