Analysis Of Recycling Mechanism Of Metallic Saturated Composites
Dorota Nagolska, Michał Szweycer Politechnika Poznańska, Instytut Technologii Materiałów, ul. Piotrowo 5, 61-138 Poznań
Annals 1 No. 1, 2001 pages 35-37
DOI:
keywords:
abstract The paper presents analysis of recycling process of the castings made of metallic saturated composites, with special attention paid to surface phenomena. As the geometry of reinforcement (Fig. 1) is hard or even impossible to describe, the way of filling the reinforcement pore for purposes of theoretical consideration has been assumed according to Fig. 2. Geometrical elements of the pores are shown in Fig. 3. Capillary pressure in the elements may be defined by relationship (1), for the angle α varying from −180° to +180°. The relationship (4) has been derived on the ground of Figures 3 and 4, assuming that x • du1 = du2.The coefficient x may be greater or less than 1. The relationship enables to calculate the pressure in the metal inside the reinforcement. The relationship (4) is shown in Fig. 5. Equating it to 0 enabled to determine critical value of the angle θkr, below which the capillary phenomena are conducive to flowing the metallic matrix out from the reinforcement capillaries. Table 1 shows the conditions and the results of composite recycling trials performed with the view to verifying the theoretical considerations. The research certifies the conclusions drawn from theoretical analysis of the recycling process of castings made of metallic saturated composites: low probability of flowing the liquid matrix out from ceramic reinforcement in air environment, as well as the fact that the better the reinforcement wetting angle with liquid matrix approximates 180°, the greater is the gain of metal derived in recycling process in an artificial e.g. slag environment.