No abstract available

[en] The erosion wear behaviors of unboiled (UB) and boiled eggshells filler reinforced epoxy composites have been characterized. The eggshells epoxy composites have been fabricated using a hand layup technique and the samples have been exposed to different environmental conditions i.e. dry, saline, mineral, kerosene and subzero temperature. To examine the effect of the above mentioned environmental conditions at different impingement angles (30, 45, 60, and 90^∘) three different particle velocities (v = 86 m/s, 101 m/s and 119 m/s) were selected for the erosion wear behavior. The highest erosion rate is found at 60^∘ impingement angle, which indicates the semi-brittle erosion nature of eggshells epoxy composites. The impingement angle and impact velocity have a notable influence on erosion rate. A fruitful effect of filler addition is observed on the erosion wear rate of composites. The erosion rates of unboiled and boiled eggshells epoxy are compared. The 4 wt% unboiled eggshells filler content shows the highest wear resistance in dry condition. The exposure of composites in different environmental conditions had a negative effect on erosion rate.

[en] Operational properties of hard alloys are investigated with reference to the processes of friction and wear. (author)

[en] Some simple considerations of the total volumetric wear rates measured in tool life tests using radioactive tools provided information on the separate contributions of flank and crater wear effects. In orthogonal cutting tests with irradiated high speed steel tools there was reasonable agreement between the results obtained using the present approach and those obtained using the Hake-Opitz method of flank-crater separation. (Auth.)

[en] In this colloquium are reviewed the development of hard materials and hardening of nuclear components undergoing friction to improve wear resistance for example primary coolant circuit vanes and particularly the development of nickel base alloys as a substitute to cobalt base alloys

[en] Silicon nitride which can be expected to replace the conventional material for scaling the shaft of Reactor Coolant Pump is tested in elevated temperature water to investigate its wear resistance. To utilize the silicon nitride at the sliding part in nuclear environment, wear behavior in the elevated temperature water should be checked. The effect of temperature on the wear behaviour of silicon nitride sliding on the same material in water were investigated in the range from room temperature to 200 .deg. C under the corresponding saturated vapor pressure. Both the specific wear rate and the friction coefficient increased at elevated temperature. The grains peel our from the wear surface at high temperature by the dissolution of inter-granular impurities, and this may be reason of high local stress on the asperity, which causes the high friction coefficient

[en] Highlights: → The influence of wear parameters on the wear rate of RLDPE were investigated. → The predicted wear rate of the RLDPE and it composites were found to lie close to that experimentally observed ones. → The results showed that the addition of bagasse ash as filler materials in RLDPE composites increase the wear resistance. -- Abstract: The tribological behaviour of recycled low density polyethylene (RLDPE) polymer composites with bagasse ash particles as a reinforcement was studied using a pin-on-disc wear rig under dry sliding conditions. The influence of wear parameters like, applied load, sliding speed, sliding distance and percentage of bagasse ash fillers, on the wear rate were investigated. A plan of experiments was performed to acquire data in a controlled way. Scanning electron microscope was used to analyse the worn surface of the samples. Linear regression equation and analysis of variance (ANOVA) were employed to investigate the influence of process parameters on the wear rate of the samples. The predicted wear rate of the RLDPE and it composites were found to lie close to that experimentally observed ones. The confirmation of the experiments conducted using ANOVA to verify the optimal testing parameters show that sliding speed and applied load had significant effect on the wear rate. The results showed that the addition of bagasse ash as filler materials in RLDPE composites increase the wear resistance of the composite greatly.

No abstract available

[en] Within the model of the mechanics of contact interaction and on the basis of the experimental data there has been examined a number of tasks that allow us to determine the dependence of the wear resistance of composite materials from changes in their structural parameters. The solutions presented in integral form include both geometric parameters of hardened areas and tribological properties of the materials. Using these solutions, the structure of cement compositions was optimized by application of the numerical experiment and response surface methodology. Optimum parameters of the wear surface for the production of high-abrasion-resistance materials were found which agree with the results of experimental data. (paper)

[en] Machinability of AISI H13 tool steel is a prominent issue since the material has the characteristics of high hardenability, excellent wear resistance, and hot toughness. A method of improving cutter life of AISI H13 tool steel plunge milling by alternating the toolpath and cutting conditions is proposed. Taguchi orthogonal array with L9 (3^4) resolution will be employed with one categorical factor of toolpath strategy (TS) and three numeric factors of cutting speed (Vc), radial depth of cut (a_e), and chip load (f_z). It is expected that there are significant differences for each application of toolpath strategy and each cutting condition factor toward the cutting force and tool wear mechanism of the machining process, and medial axis transform toolpath could provide a better tool life improvement by a reduction of cutting force during machining. (paper)