Classification of Structure Defects of Metal Matrix Castings with Saturated Reinforcement

Abstract

Definition of a composite [1] describes an ideal composite material with perfect structure. In real composite materials, structure is usually imperfect - composites contain various types of defects [2, 3-5], especially as the casted composites are of concern. The reason for this is a specific structure of castings, related to course of the manufacturing process. In case of metal matrix composite castings, especially regarding these manufactured by saturation, there is no classification of these defects [2, 4]. Classification of defects in castings of classic materials (cast iron, cast steel, non-ferrous alloys) is insufficient and requires completion of specific defects of mentioned materials. This problem (noted during manufacturing metal matrix composite castings with saturated reinforcement in Institute of Basic Technical Sciences of Maritime University Szczecin) has become a reason of starting work aimed at creating such classification. As a result, this paper was prepared. It can contribute to improvement of quality of studied materials and, as a consequence, improve the environment protection level.

Hybrid Comopsites Shaped by Casting Methods

“…For investigations of the structure of ceramic particles distribution over cross-section of the casts as well as for tribological tests, adequate samples were prepared. In accordance with the assumed methodology [16], a number of geometric parameters were determined. For analysis of the influence of applied centrifugal casting technology on distribution of ceramic reinforcement in the composite sleeves the volume fraction of particles (Vp) and average value of particle size (Feret's diameter) were used.…”

Crystallisation of Silicon on Reinforcement Fibres as a Consequence of Overheating of Matrix Metal during Saturation in MMC

“…In order to confirm this phenomenon it is still necessary to carry out further studies, namely the observation of composite structure on fractures using scanning electron microscopy and the influence of alloys of aluminium with silicon on carbon in high temperatures. Such investigation should also include the observation of the phases on the matrix-reinforcement boundary [7,9]. Consequently, it is necessary to carry out strength tests of materials with overheated matrix.…”

“…The study was performed on the material composite made by saturating short carbide fibre reinforcing profiles with liquid alloy of AlSi11 (Fig. 3) under the pressure of 15 MPa in the period of 300 seconds, satisfying all requirements of the technology of castings produced by saturating with the method of liquid metal moulding [8][9]. The following experiment was carried out to examine the influence of the matrix temperature on the reinforcement phase.…”

“…In eutectic aluminium alloys, due to non-equilibrium crystallisation conditions, original silicon crystals tend to precipitate [10][11]. As the possibility of silicon nucleation on carbon substrate has been found, one can expect phase α precipitates in the vicinity of or directly on carbon fibres [5,7,[9][10][11][12].…”

Archives of Foundry Engineering

“…of ceramic particles, respectively. Parameters [15] play a key role in the production of infiltrated composites. The infiltration of the liquid matrix of free spaces in preforms was carried out on a hydraulic press using the squeeze casting method at the following parameters:…”