Authors: S. Manoharan, G. Ramadoss, B. Suresha, R. Vijay
Abstract: In the present study, enhancement of abrasion resistance of phenol formaldehyde (PF) resin based hybrid friction composites with different ingredients viz. binder, micron sized fibers and fillers have been synergistically investigated. Hybrid friction composites based on basalt and recycled aramid fibers were prepared using compression moulding. Three-body abrasive wear tests were conducted according to ASTM G-65 standard by dry sand/rubber wheel abrasion tester using two different size of angular silica sand abrasives (212 and 425 μm) at a constant load of 40 N. The results indicated that the wear volume loss increases with increasing abrading distance and abrasive particle size. However, the specific wear rate decreased with increasing abrading distance and increases with increase in abrasive particle size. Addition of fiber content has a significant influence on the abrasive wear performance of these composites. Further, the worn surfaces were examined by scanning electron microscopy to identify the involved wear mechanisms.
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Authors: Kristjan Juhani, Jüri Pirso, Marek Tarraste, Mart Viljus, Taavi Suurkivi
Abstract: WC-Co hardmetals are widely known wear resistant materials, their properties depend strongly on the WC grain size; commonly fine grained materials exhibited higher properties. One opportunity to produce fine grained materials is reactive sintering. Reactive sintering is a novel processing method, where the synthesis of the carbide phase is combined with solid and liquid state sintering of the composite during a single heating cycle. WC-co hardmetals where synthesized in situ from the elemental powders of W, Co and C. To investigate the influence of grain growth inhibitors the Cr3C2 and VC were also included to powder mixtures. To investigate the influence of carbon content composites with different amounts of C were produced. The microstructures, hardness and three-body abrasive wear resistance of reactive sintered WC-Co hardmetals with grain growth inhibitors depending on carbon content in initial powder mixture is exhibited.
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Authors: C. Anand Chairman, S.P. Kumaresh Babu
Abstract: Three-body abrasive wear behavior of basalt–epoxy (B–E) and glass–epoxy (G–E) composites have been investigated using Dry sand rubber wheel abrasion resistance for various abrading distance, viz., 150, 300, 450 and 600m and different loads(22N and 32N) at 200 rpm. The weight loss and specific wear rate as a function of load and abrading distance were determined. The weight loss increases with increasing load and also with abrading distance while the specific wear rate decreases with increase in abrading distance and increases with the load. Better abrasion wear resistance was observed in B-E composite compared to G–E composite. Scanning Electron Microscope (SEM) is used to examine the abraded composite specimens and revealed that the more damage occur to glass fiber compared to basalt fiber. Also good interfacial adhesion was observed between epoxy and basalt fiber which leads to good abrasive wear resistance.
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Authors: B. Suresha, T. Jayaraju, P.R. Sadananda Rao, Mohammed Ismail, Kunigal N. Shivakumar
Abstract: Fiber reinforced polymer composites are generally known to possess high
strength and attractive wear resistance in dry sliding conditions. The behaviour of such
composites performing in abrasive wear situations needs a proper understanding. Hence,
in the present work of the three-body abrasive wear behaviour of two dimensional stitched
carbon fabric, E-glass woven fabric and three dimensional E-glass woven fabric reinforced
vinyl ester composites was investigated. Three-body abrasive wear tests were conducted
using rubber wheel abrasion tester (RWAT) under different abrading distances at two
loads, wherein the wear volume loss were found to increase and that of specific wear rate
decrease. The results indicate that the type of fabric in vinyl ester have a significant
influence on wear under varied abrading distance/loads. Further, it was found that carbon
fabric reinforced vinyl ester composite exhibited lower wear rate compared to E-glass
woven fabric reinforced vinyl ester composites. The worn surface features, as examined
through scanning electron microscope (SEM), show higher levels of broken glass fiber in
two dimensional glass woven fabric reinforced vinyl ester composite compared to carbon
fabric and three dimensional glass fabric reinforced vinyl ester composites.
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Authors: Guo Shang Zhang, Yi Min Gao, Jian Dong Xing, Shi Zhong Wei, Xi Liang Zhang
Abstract: To improve the wear resistance of high chromium white cast iron under severe abrasive
conditions, a composites layer was designed for wear surface, which were locally reinforced with WC
particles. And the local composites were successfully fabricated by optimized centrifugal casting
process. Then the interface between WC and iron matrix was analyzed with scanning electron
microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). And
three body wear tests were carried out on a self-made rig to investigate the wear resistance of the
composites. For comparison, the wear tests of high chromium white cast iron were also carried out
under the same conditions. The results show that: There are no defects such as inclusion, crack, gas
pore and so on in the obtained composites layer, which with a uniform thickness of 10 mm. WC
particles are homogeneously distributed in the composites layer and tightly bonded with the iron
matrix. The WC particles are partially dissolved in the iron matrix during centrifugal casting. The
elements W, C and Fe react to form new carbides such as Fe3W3C or M23C6, which precipitate around
former WC particles during subsequent solidification. So the interface between WC particles and the
iron matrix is a strong metallurgical bonding. WC particles in the composites layer can effectively
resist cutting by the abrasive, and then protect the matrix. The wear resistance of the composites layer
is 7.23 times of that of high chromium cast iron.
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