epoxy before cutting a slice with a thickness of 2-3 mm. This slice was spread with particle 
reinforced epoxy to give maximum stability for the cell walls. The mounted samples were manually Gelußt 
ground and polished as described in table 1. After passing the grinding step at mesh 1200 the 
samples were carefully vacuum-infiltrated with epoxy to fill open pores and then prepared Heidi X 
continuing with SiC at mesh 1200 using a Phönix 4000 V. Special attention had to be paid at the Kr 
preparation times and pressures. These were different depending on the preparation target: optimal en 
preparation of the foam needed longer polishing times, resulting in inducing artifacts into the 
thermally sprayed coating. Final polishing with OPS or polishing alumina caused outbreaks of Proble 
phases out of the coating. Good contrast was obtained deposing zincselenid (ZnSe) onto the sample far 
and using optical interference contrast. Etching methods still are under investigation. we De 
Grinding (300 U/min), SiC Polishing ed 
150 U/min) _ co 
Mesh | 180 | 400 | 800 | 1200 | 1200 | 2400 | 4000 3p 14 vo 
Time | 1 1 1 1 1 1 1) oe 4 NE 
Pressure | pec ' ~5 | 25 | 25 | 25 | 25 25 | 2,3 2,3 
jpar] y 7 7 ' ' ’ ! oo ' . , 
ET etal rear a Einlei 
able 1: Metallographic preparation recipe for samples of © 30mm oo 
5 Conclusion nes 
[ERE 
Body-L 
Thermal spraying proved to be a suitable technique for coating metal foams, obtaining a good N 
surface finish. Suitable substrate preparation and spraying parameters were developed for metal hd 
foams. Metallographic preparation methods had to be adjusted for the combination of a relatively gin 
hard coating layer on top of soft aluminium foam. © . 
[em 
| Brews 
6 Literature fee 
[1] S.Leigh, S.Sampath, H.Herman, C.Berndt: ,,Mechanical properties of water stabilized plasma Mate 
spray-formed...“, proc. 13" Int. Spray Conf., Ohio, USA, 1996, pp. 835-840 nr 
[2] S.Leigh, G.Lee, C.Berndt: „Modelling of elastic constants of plasma spray deposits...‘“, proc. Die : 
15° Int. Spray Conf., Nice, France, 1998, pp. 587-592 ane 
[3] X.Wang, J.Heberlein et al. „Effect of gas velocity and particle velocity on coating adhesion in Schwe 
wire arc spraying“, proc. 13” Int. Spray Conf., Ohio, USA, 1996, pp. 807-811 Teilm 
[4] H.F.Voggenreiter: „Prozeßoptimierung des Hochgeschwindigkeitsflamm-spritzens für die Die Zi 
Herstellung lasttragender Strukturen...‘“, Diss. Herbert Utz Verlag, München, ISBN: 3-89675- 
150-6, 1996 
[51 L.Gibson, M.Ashby: „Cellular Solids‘“, Cambridge University Press, ISBN: 0-521-49911-9, kon 
1999 
338