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1. ADVANCED MATERIALS AND COMPOSITES:FROM POWDER TO PART Assoc. Prof. Dr. Alpagut KARA
2. MANUFACTURE
3. MANUFACTURE
4. MANUFACTURE - Raw materials and additives
5. MANUFACTURE - Raw materials and additives
6. There are two possibilities:
a) The ceramic manufacturer acquires the necessary raw materials and carries out all further processing tasks.
Specific preparations of unfired material are required for the different forming processes:
7. MANUFACTURE - Body preparation
8. Methods of shaping ceramic parts can be divided into the following basic types:
pressing (0 – 15 % moisture)
plastic forming (15-25 % moisture)
casting (> 25 % moisture), and others.
9. MANUFACTURE – Forming ? Dry pressing
10. MANUFACTURE – Forming ? Isostatic pressing
11. Allows the manufacture of parts with complex geometries such as screw threads, side holes, recesses and undercuts. The unfired material used for this purpose usually has moisture levels in the range of 10 to 15%. Compressing with a single axis makes these
materials able to flow freely, so that relatively even compression can be achieved.
The disadvantage of this, however, is that wet pressing materials can accept only low compressive strains. This also means that the degree of compression is limited. It depends heavily on the moisture content of the unfired material, and is lower than in the case of dry pressed parts. MANUFACTURE – Forming ? Wet pressing
12. MANUFACTURE – Forming ? Extrusion
13. Principally suited to the mass production of complex products. It is limited by relatively high die costs and the complex burnout of organic additives. The conveying
capacity ("shot weight") of large injection moulding machines is typically up to about 70g. Generally, the part should be designed so that thicknesses are as consistent as possible, having an upper limit of approx. 12 mm. MANUFACTURE – Forming ? Injection Moulding
14. A simple method for the manufacture of prototypes, parts with complex geometries and relatively large items. It can be used to manufacture both thin-walled and solid objects. Ceramic slip casting involves a stable suspension, referred to as the slip, being poured into a porous, absorbent plaster mould. Extraction of the suspending liquid causes a layer of particles to develop on the mould wall. This layer develops, in solid casting, to create the fully molded body. In the case of hollow casting, the superfluous slip is poured out once the desired wall thickness has been achieved. MANUFACTURE – Forming ? Slip Casting
15. MANUFACTURE – Forming ? Tape Casting
16. MANUFACTURE
18. FROM FORMING TO FIRING
19. FIRING
20. FIRING
21. FIRING
22. DIMENSIONS & SHRINKAGE
23. DIMENSIONS & SHRINKAGE
24. MACHINING
25. MACHINING – Green machining
26. MACHINING – White machining
27. FINAL MACHINING – Hard machining
28. FINAL MACHINING – Possible finishing processes
29. Ground Surfaces
30. Ground Surfaces
31. HONED SURFACES
32. LAPPED SURFACES
33. LAPPED SURFACES - Model of material removal by lapping
34. POLISHED SURFACES
35. CERAMIC COATINGS
36. CERAMIC COATINGS
37. CERAMIC COATINGS
38. CERAMIC COATINGS