More and more companies are moving from traditional manufacturing to additive manufacturing as a way of gaining competitive advantage on the market. However most of the times an additive manufactured part needs post processing for a nice smooth end product finish.
In this case study we will look at how you can mass finish a 3D printed part manufactured using a 3D mesh.
Recently we had the opportunity to develop a finishing process for an additive manufacturing company, that builds 3D parts for a wide array of engineering sectors. This project required finishing an additive manufactured Inconel wheel. The part end finish implied a high polished surface on one side of the wheel whilst leaving the other untouched.
The entire component is built via additive manufacturing and it includes a 3D mesh. Hence whilst the front side appears smooth the back of the component would comprise of a very fine mesh with numerous gaps. Therefore, the mesh side of the part must be completely covered to an air tight tolerance during any mass finishing process. This ensures that no lodgement of media can contaminate the mesh side and no impingement of the structural integrity of the wheel.
Solution developed for the additive manufacturing company
We examined the component and determined that a masking solution should be developed to cover the mesh side. We designed the masking solution to be air tight in order to not move while the part was processed.
The technology used to finish the wheel is the Centrifugal High Energy machine. Due to previous studies conducted by ActOn the CHE technology is perfect for finishing 3D parts as:
- processing time, via CHE technology, is shorter than traditional methods
- CHE machines are great for removal of surface defects and improving the surface finish
- There is no need for major tooling and no need for fixturing
- The results are consistent and repeatable
Taking into consideration the force created by the high energy process, we made sure the masking was bolted onto the component.
The trial conducted includes 3 stages:
- We carried out the first stage by deburring the wheel in the CHE40 machine with an abrasive ceramic media and an acidic compound. This compound is great for removing scale, brightening and polishing ferrous metals.
- To smooth the surface we used a medium abrasive ceramic media and the same acidic compound. For a more effective process we finished the parts in the same finishing machine.
- The last stage included polishing the surface in the CH40 machine using only pre-treated media. In the high energy machine it has been proved that the pre-treated media produces a bright mirror finish in a reduced time.
This process achieved a 90% loss in roughness average, as requested by the customer (see table below for specific data). The masking solution developed by us was successful and completely protected the rear side of the component. Furthermore the polished finish required on one of the surface was achieved in only 3 hours without affecting the other side of the wheel.
|Part Identifier||Roughness Average Before Process (µm)||Roughness Average After Process (µm)||Total Ra Loss (µm)||%Ra Loss|
|3D printed part||4.814||0.453||4.361||90.6|