Thinking about additive manufacturing for metal components?
The way we manufacture is changing. Many new developments and technologies are being harnessed to increase production efficiency, reduce costs, make customisation easier and better optimise products. Additive manufacturing (or 3D printing) is one area that is growing quickly in its capability to cover larger components and meet different mechanical or chemical needs. For design engineers it can remove previous component limitations bound by how a part needs to be machined. For production managers it can reduce lead times and increase manufacturing flexibility. It can also lower production costs while enhancing the benefits of a component. Is it no wonder, therefore, that leading companies are investing in this technology for the future of their businesses?
Rina Consulting - Centro Sviluppo Materiali (CSM) is part of the Rina group. With a background in developing steel technologies, it specialises in helping companies that wish to incorporate additive Manufacturing (AM) into their metal business. It can help with everything from feasibility of the process for the application through to selection of material, development of specific materials with special characteristics if required, and verifying resulting products.
AM uses metals, composites or plastics typically in a fine powder form. Using various techniques such as lasers and electron beams, machines build up layers of the powdered material to form a component. If we talk about metal powders, there are currently less than 30 such powders generally available that cover a wide range of mechanical and chemical needs. If these powders do not have the specific characteristics required, companies such as CSM can develop new variants to meet requirements.
Guido Chiappa, CEO at CSM comments, “Although it may appear that the first step of embracing AM is to select a machine for the process, this is not the starting point. First of all it must be established how components or products are connected to the options enabled by AM. This dictates which particular AM process, and so machine, is required to best meet application needs.”
Components and bills of materials need to be analysed to see which items are made of which materials and where benefits of AM may lie. It may be there is a production bottleneck with time to supply where AM can help. Other benefits and reasons for change may include the cost of machining a particular part, or a part that is not best optimised because of the constraints of machining. There may also be general areas where more flexibility in supply may benefit an organisation, for example the ability to produce small batches or easy customization. Once evaluated and benefits identified, the next step is to consider what requirements are connected to the component and whether technology exists today to meet these or not. If not, can a special metallic or alloy powder be developed that will meet the needs of the component?
For some market areas, such as major power generation or aeronautics businesses, AM is so appealing as a future technology that it will be decided that some components will be developed using AM even if the AM technology needs further development. This development will then form part of the overall project. This is obviously a major commitment and investment but new powders can be designed to meet specific needs.
Designing new metallic or alloy powders for use in AM is an iterative process. The powder is designed for specific chemical or mechanical requirements based on existing material properties. This then needs to be trialled in pilot production and the product tested to verify its characteristics are as required. Of course, tests and qualification of the final process needs to be carried out on the specific AM machine type that will be used in final production.
To help businesses realise the benefits AM has to offer, a number of areas of expertise are required. These include detailed understanding of the compositions and chemistry of the powders used, in-depth knowledge of the different AM technologies and how they are best used, and the facilities to test the complete process prior to investment in full scale machines. State-of-the-art laboratories and production facilities are needed for such testing with careful analysis of the resulting components. If new powders are needed, these need to be manufactured and tested.
Consultants in AM also need to be able to support companies in understanding the return on investment with technical and economic feasibility for their specific applications. This includes helping identify current components and sub-components suitable for the process as well as views on future growth potential and increased competitiveness through the integration of AM technology.
One of the major appeals of AM is the freedom of the constraints of traditional manufacturing processes. Geometries ergonomics and overall design can be optimised along with the potential for reducing the number of manufacturing steps. This revolutionises components’ designing, enabling geometries to place strength and integrity precisely where they are required. This can not only add benefit to the final product in terms of features and characteristics but can also increase component reliability and help ensure consistent high quality.
An increase in reliability and assured quality has general appeal but in industries such as oil and gas, it is of particular importance and interest. Oil and gas installations are often in some of the harshest environments found on the planet. As AM technology develops to offer larger and larger component sizes, the technology presents many benefits in wider applications. Special metallic and alloy powders can be selected or developed that can specifically handle extremes in corrosion, pressure and temperature. Companies such as CSM offer the additional peace of mind of detailed understanding of the application of the materials used in this industry and can test and validate new products for ultimate safety and security.
The limitation on size and material availability will be resolved in the future and 3D printing will become a technology complementing and completing the standard one.
Some key industrial application examples include the medical and aerospace industry. AM techniques have been applied within the medical and dental practice for the creation of assistive, surgical and prosthetic devices, surgical implants and scaffolds for tissue engineering. Applications have gained widespread interest due to the nature of the process allowing complex parts to be created specifically for the patient directly from a 3D CAD model.
For the aerospace industry one of the key drivers in components manufacturing is to improve the buy-to-fly ratio of metallic parts. Topology optimisation to create complex structures and to reduce the weight is another important key driver.
Summary
Additive manufacturing is changing the engineering design world. As this exciting new technology continues to develop, the number of applications that will benefit from it continues to increase. Furthermore, the additional support from advances such as the Industry 4.0 model and Internet of Things will promote wider use of this technology.
With specialist support, businesses can plan to incorporate the technology into their production lines with peace of mind that processes have been tested and validated prior to full-scale investment. Companies such as CSM can give independent advice to ensure the best return on investment and trouble-free implementation of the technology. Understanding the composition of the powders, the machinery options available, limitations and applications where materials are used as well as being able to develop, produce samples and thoroughly test new powders or AM processes are all part of getting the best out of AM for each individual business need.
