Leading the way in metal 3D printing in the Southern Hemisphere, RAM3D has been involved in additive manufacturing for 10 years from its base in New Zealand.
RAM3D is a metal 3D printing facility and high-tech manufacturing company producing parts for a diverse array of industries world-wide. The technology has greatly advanced over the past five years and RAM3D has seen a shift from prototyping to include full production work. This is possibly a result of the early adopters of the technology starting to move their projects increasingly through the project stage.
The two key drivers to this transition are:
- Designers have recognised that the technology opens different design avenues. They can look at the areas of function and load and only place material where it is needed. This design freedom results in a highly optimised part in both functionality and cost.
- The cost of production by 3D printing has reduced. RAM3D operates four machines; they have been able to cover their overheads and apply the lessons they have learned over time to refine the process and ultimately bring benefits to companies having parts made.
Throughout most of the world, two of the early adopters of 3D printing technology are the high-priced aerospace and medical sectors. This has limited the growth of the industry in other sectors because of the desire for the cost of 3D parts to be more cost-effective.
In New Zealand there is limited medical and aerospace markets and RAM3D has focussed on the wider market to meet the price point to make it work. As a result, the market sectors engaged are much broader. The result is some very innovative products.
Case studies
One of these innovative products is firearm suppressors. RAM3D has been working in collaboration with Oceania Defence, an early adopter of additive manufacturing technology, to 3D print the most advanced firearms suppressors in the world. After rigorous design, research and testing with Oceania Defence, they have achieved the most desired outcome: a suppressor that is highly efficient, lightweight, compact and, most importantly, cost-effective.
RAM3D has been building drone engine parts for another company. The three-cylinder engine has a weight of 50kg and aircraft wingspan of 6m; it can fly to heights of 5,500m and has a cruise speed of 60 knots. The parts that RAM3D prints for them cannot be manufactured any other way and are printed in Inconel 718, a high-temperature alloy, requiring high precision especially where mass matters. It has printed production runs of manifolds, exhaust mufflers, collectors and more recently engine sumps.
Another innovative product is Bastion Cycles’ custom bicycle using 3D printed lugs and carbonfibre tubing. This Melbourne-based company’s titanium (Ti 6Al 4V) lugs are a great example of the technology being applied in true mass customisation. RAM3D started working with Bastion Cycles in 2015 and through collaboration on design has seen over 100 custom bikes made. RAM3D currently produces 3D printed parts for a few other bike manufacturers on the world-wide stage.
RAM3D uses a variety of advanced materials for additive manufacturing, including:
- Titanium 64 (Ti 6AI 4V) – The most common titanium alloy, used for medical and aerospace applications. It boasts the highest strength-to-weight ratio of engineering metals and is extremely corrosion-resistant.
- Stainless Steel 15-5ph – This provides high strength, moderate corrosion resistance and good mechanical properties at temperatures up to 316°C. It is a hardenable stainless steel up to 48 HRC. It is widely used in the aerospace, chemical, petrochemical, food processing industries.
- Stainless Steel 316 – This has excellent corrosion resistance in a wide range of media, which makes it particularly desirable for applications where exposure to salt is an issue. It is mainly used in the food sector, marine and dairy industries.
- Inconel 718 – This is a nickel super-alloy used for high-temperature applications and is used in a variety of industries such as aerospace, chemical processing, marine engineering and oil and gas.
Post-processing options
Once a part has been 3D printed and the support material has been removed, the part undergoes a media blasting process. Media blasting gives a more uniform finish and it suits most applications where the customer doesn’t require a polished finish. RAM3D often compares the standard finish to the surface of a mandarin orange.
All the company’s titanium printed parts are heat-treated in order to: reduce residual stresses developed during fabrication (stress relieving); and to produce an optimum combination of ductility, machinability, and dimensional and structural stability (annealing). RAM3D can also heat-treat Inconel 718 and Stainless Steel 15-5ph.
RAM3D also offers a number of polishing options:
- Vibratory polishing. The standard finished part is put it into the vibratory polisher where it is immersed in mixed ceramic media and left for a period of time until it becomes polished. This process can take sharp edges off certain features.
- Hand polishing. This requires a hands-on approach involving grinding, linishing and hand sanding before moving on to buffing and polishing. Many parts are not suitable for hand polishing; it can be quite time-consuming and is a more expensive option.
Quality control
Quality control is an important part of the design and manufacturing process, with finished pieces needing to be consistently reliable. RAM3D has developed what the team believes is a key part of quality control; they build tensile bars with every build and test them. Over the past 10 years this has resulted in literally thousands of tensile tests. They keep all the results and bars to ensure traceability over every build.
This process has enabled them to develop an understanding of the key factors influencing the selective laser melting process, from laser parameters to gas flow and powder quality. Over the years they have built a quality control process that gives them a large amount of data from a single test. The comparison of each test against historical norms tells them very quickly if the build could be out of specification. The best part is it is very cost-effective, helping to keep the costs to customers to a minimum, but they have found the key is the tracking against historical data to quickly highlight even very small variations.
3D printing won’t do everything; it is another tool in the toolbox just like casting and machining. However, when used well, it can create new products and achieve new goals.