Metal 3D printed Hydraulic valve:
Traditional manufacturing versus Additive manufacturing
At aidro, we are fascinated by the potential of Additive Manufacturing, such as lighter forms and the fast production lead time, just to say some of them.
There are many advantages to using 3D printing not only for innovative industries, such as aerospace and automotive, but also in a traditional sector as Hydraulics.
However, when you think about the introduction of a new technology in a long-established industry, it is important to go deeper, to evaluate many aspects and make a clear comparison between the old and the new. We will try to make this comparison in the following lines.
First of all, we want to take into account the main manufacturing methods that can be used to produce hydraulic components:
1- traditional manufacturing: starting with a larger piece of material, layers are removed, or subtracted, to leave the desired shape with CNC Machining. The starting workpiece is derived from a metal casting mold or from a metal bar.
2- additive manufacturing: we consider only Metal 3D printing, because generally, metal parts are used in most hydraulic systems due to their high pressure ratings. Plastics 3D printing is most popular and plastic have naturally higher resistance to corrosion than metals but have lower strength and durability, making them less suitable for hydraulic systems.
There are several techniques of Metal 3D printing and we think the most suitable for Hydraulics, at the moment, is the Powder Bed Fusion (SLM Selective Laser Melting or DMLS Direct Metal Laser Sintering).
Further, we list what are the elements to consider when comparing the technologies for the production of hydraulic parts. It is important to first identify the customer’s needs, as follows:
1) Quantity: traditional manufacturing is more suitable for large-scale production, whereas 3D printing may be more economical for small volumes of complex hydraulic components.
2) Production lead time: subtractive process can take up to 30-60 days in case of CNC machining from metal bar or take a few months (from 6 to 12 months) in case of casting. For 3D printing, the hydraulic components can be printed on demand in a matter of days. If the printed parts require a tooling, the lead time may increase up to 1 or 2 weeks.
3) Prototyping: in this case, the added value of 3D printing is that you can print at the same time different models of the same prototype.
4) Material selection: oil hydraulic products’ materials must have adequate strength and corrosion resistance to safely handle the high pressures characteristic of hydraulic systems. The most common materials used in traditional Hydraulics are carbon steel, stainless steel and aluminum. The 3D printing can offer a higher materials selection with the same manufacturing process, at choice between: stainless steel (AISI316L, 17-4PH), aluminum, titanium (Ti6Al4V), Inconel (625 or 718), Maraging steel, for example.
Therefore, the additive manufacturing of hydraulic components is a good alternative to traditional production methods, in some cases, in order to solve some problems of production and to respond promptly to customers requirements.
So to illustrate these thoughts, see hereunder a case history of hydraulic valve made by aidro Hydraulics
Some time ago, a customer asked us a small series of stackable valve made in stainless steel. The standard direct operated pressure reducing valves are made in steel zinc plated and to produce a low volume of pieces the CNC machining is too expensive. So the solution was clear: produce the requested valves with additive manufacturing.
The result is a redesigned hydraulic valve body with a new lightweight form. The weight is 60% less, the structural walls are solid as the original piece. The performance was tested at 250 bar pressure and the results are as good as the traditional valve.
See the comparison hereunder:
Our customer was satisfied with this 3D printed hydraulic valve made in stainless steel and the fast lead time convinced him to accept the new technology and his price !
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