Wear resistance of TiC-cast steel metal matrix composite has been investigated. Composites were obtained with SHSB method known as
SHS synthesis during casting. It has been shown the differences in wear between composite and base cast steel. The Miller slurry
machine test were used to determine wear loss of the specimens. The slurry was composed of SiC and water. The worn surface of
specimens after test, were studied by SEM. Experimental observation has shown that surface of composite zone is not homogenous and
consist the matrix lakes. Microscopic observations revealed the long grooves with SiC particles indented in the base alloy area, and
spalling pits in the composite area. Due to the presence of TiC carbides on composite layer, specimens with TiC reinforced cast steel
exhibited higher abrasion resistance. The wear of TiC reinforced cast steel mechanism was initially by wearing of soft matrix and in
second stage by polishing and spalling of TiC. Summary weight loss after 16hr test was 0,14÷0,23 g for composite specimens and 0,90 g
for base steel
The article presents chosen aspects of foundry engineering of the settlement dwellers, including the archaeometric characteristics and
metal science analysis of the artefacts, as well as an attempted reconstruction of the production organization. Discovered in Szczepidło
(Greater Poland), the foundry workshop is unique in Central European Bronze Age.
This workshop foundry operated roughly XIV-XII Century BC. Its production is evidenced by the presence of markers of the whole
production cycle: semi-finished and finished products, production waste, fragments of crucibles and casting ladles with traces of usage,
and tools. On this basis, the alloys and foundry technologies used have been described.
The analysis of foundry technology of copper alloys in the settlement area was carried out by observing the surface and structure of the
products, semi-finished artefacts and fragments of crucibles by applying optical microscopy (OM), confocal microscopy (CLSM) and Xray
radiography (RT). The investigations of compositions were made by means of the energy dispersive X-ray fluorescence spectroscopy
(ED-XRF) and scanning electron microscopy (SEM) coupled with an energy dispersive X-ray analysis system (EDS).
The study presents the results of research on the development of composite zones in castings based on the intermetallic phase of Ni3Al. Composite zones were obtained by placing packets with substrates for the reaction of titanium carbide in a foundry mould. To provide a variable carbides content in the composite zone, two compositions of the packets were prepared. The first packet contained only substrates for the reaction of TiC synthesis; the second one also contained a filler. The resulting composite zones in castings were examined for the filler effect on changes in the volume fraction, size and morphology of carbides in the zone. In addition, the effect of filler on the mechanical properties of the zone was verified, observing changes of Vickers hardness in this area. It was found that the presence of filler in the composition of the packet for synthesis reduced the content of carbides, as well as their size and morphology. Lower surface content of carbides reduced hardness of the zone, which enabled smooth control of the mechanical properties. At the same time, the use of the selected filler did not disturb the course of the TiC carbide synthesis.
In order to increase wear resistance cast steel casting the TiC-Fe-Cr type composite zones were fabricated. These zones were obtained by
means of in situ synthesis of substrates of the reaction TiC with a moderator of a chemical composition of white cast iron with nickel of
the Ni-Hard type 4. The synthesis was carried out directly in the mould cavity. The moderator was applied to control the reactive
infiltration occurring during the TiC synthesis. The microstructure of composite zones was investigated by electron scanning microscopy,
using the backscattered electron mode. The structure of composite zones was verified by the X-ray diffraction method. The hardness of
composite zones, cast steel base alloy and the reference samples such as white chromium cast iron with 14 % Cr and 20 % Cr, manganese
cast steel 18 % Mn was measured by Vickers test. The wear resistance of the composite zone and the reference samples examined by ballon-disc
wear test. Dimensionally stable composite zones were obtained containing submicron sizes TiC particles uniformly distributed in
the matrix. The macro and microstructure of the composite zone ensured three times hardness increase in comparison to the cast steel base
alloy and one and a half times increase in comparison to the white chromium cast iron 20 % Cr. Finally ball-on-disc wear rate of the
composite zone was five times lower than chromium white cast iron containing 20 % Cr.
Refinement is one of the most energy consuming technological process, aimed at obtaining mineral raw materials of the proper grain size.
Cast structural elements such as jaws or hammers in crushing machines operate under conditions of an intensive wear. The data indicate
that 80 % of failures of machines and devices is caused by wearing of rubbing surfaces. This problem became the subject of several
scientific and industrial investigations carried out in the whole world in order to produce materials ultra- wear resistant. Methods allowing
to obtain wear resistant composite castings are discussed in the hereby paper. Within the performed research microstructures of the
produced composite zones were presented and the comparative analysis with regard to mechanical and functional properties of local
composite reinforcements in relation to the commercial alloys of increased wear resistance was performed. The results show almost twenty
five times increase in wear resistance compared to manganese cast steel containing 18 % Mn.
The article presents research aimed at determining the effect of adding rare earth elements to near-eutectic Al-Si and Al-Si-Ni alloys on the microstructure and mechanical properties of the obtained products. Material for the research was prepared using a melt spinner – a device used for rapid crystallization, casting thin ribbons, which were then subjected in subsequent stages to fragmentation, consolidation and plastic working. The ribbons and extruded rods cast were described in terms of their structure and their strength properties were determined at different measurement temperatures. It was shown that the lightweight materials produced from aluminium alloys using the rapid solidification process have an ultra-fine structure and good strength properties.
Analysis under a microscope confirmed that the addition of rare earth alloys Al-Si and Al-Si-Ni causes fragmentation of the microstructure in the tapes produced. The presence of rare earth elements in the alloys tested has an impact on the type and the morphology of the particles of the microstructure’s individual components. In addition to the change in particle morphology, the phenomenon of the separation of numerous nanometric particles of intermetallic phases containing rare earth elements was also observed. The change in microstructure caused by the addition of rare earth elements in the form of a mischmetal increases the mechanical properties.