Three-body abrasion : influence of applied load on bed thickness and particle size distribution in abrasive processes

Lapping experiments at various loads showed a decreasing bed thickness with increasing applied loads. Comparison of these results with the particle size distribution, measured before and after abrasion, revealed that at higher applied loads more particles will fracture during abrasion. This also may be the cause of the slightly decreasing bed thickness in time. A quantitative interpretation of the particle size distributions was not possible, since there was a significant amount of glass present in the slurry. Nevertheless, it was clear that the actual particle size distribution under the workpiece is different from the original particle size distribution

Laser induced chemical vapour deposition of TiN coatings at atmospheric pressure

Laser induced Chemical Vapour Deposition of a wide variety of materials has been studied extensively at reduced pressures. However, for this technique to be economically and industrially applicable, processes at atmospheric pressure are preferred. A model study was made on the substrate-coating system molybdenum-titaniumnitride focussing on the feasibility to deposit TiN films locally at atmospheric pressure. The results of this study turned out to be very promising. A Nd-YAG laser beam ([MATH] = 1064 nm), directed perpendicular to the substrate, is used to locally heat the substrate (pyrolytic atmospheric pressure Laser induced Chemical Vapour Deposition). The reactive atmosphere consists of TiCl4, N2 and H2. The Laser Chemical Vapour Deposited nitride coating is characterized by SEM, EDAX, XRD, XPS, SAM and microhardness tests. The results show that the coatings are pure, polycrystalline, stoichiometric TiN with a hardness in the range 1900 to 2300 HV. The influence of laser irradiation parameters on the temperature distribution induced in molybdenum and on the deposit shape, spatial distribution and microstructure of TiN films has been studied. A fast laser spot pyrometer was built for the in-situ temperature measurements. Depending on the deposition conditions, different types of profiles, microstructures and distribution widths are observed. Two examples of atmospheric pressure Laser CVD deposited TiN films on 3D-objects are given

Fracture characteristics of abrasive particles

Particle degradation occurs during abrasive processes like three-body abrasion and erosion. With a single particle crusher strength tests have been performed with AI2O3 powders in order to gain more information about the fracture characteristics of the abrasive particles. The mean fracture force increases with increasing particle size and is larger for the used powders than for the original powders. These results are compared with degradation measurements on recycled alumina powders in erosion processes. Modelling considerations are briefly discussed in this paper

Fracture characteristics of abrasive particles

Particle degradation occurs during abrasive processes like three-body abrasion and erosion. With a single particle crusher strength tests have been performed with AI2O3 powders in order to gain more information about the fracture characteristics of the abrasive particles. The mean fracture force increases with increasing particle size and is larger for the used powders than for the original powders. These results are compared with degradation measurements on recycled alumina powders in erosion processes. Modelling considerations are briefly discussed in this paper

Three-body abrasion : influence of applied load on bed thickness and particle size distribution in abrasive processes

Lapping experiments at various loads showed a decreasing bed thickness with increasing applied loads. Comparison of these results with the particle size distribution, measured before and after abrasion, revealed that at higher applied loads more particles will fracture during abrasion. This also may be the cause of the slightly decreasing bed thickness in time. A quantitative interpretation of the particle size distributions was not possible, since there was a significant amount of glass present in the slurry. Nevertheless, it was clear that the actual particle size distribution under the workpiece is different from the original particle size distribution

Correction: bed thickness and particle size distribution in three-body abrasion

No abstrac