Wear and friction of Y-TZP spheres reciprocating against various Sialon plates

The friction and wear characteristics of various Y2O3-stabilized tetragonal ZrO2 polycrystal (Y-TZP)-Sialon sliding systems were examd. These systems consisted of a Y-TZP sphere reciprocating against various Sialon plates. The Sialons differed in phase content and compn. They range from a-Sialons to b-Sialons and include a-b composites. The length of the wear tracks was 10 mm, the loads used were 2 and 8 N, the frequencies 1, 4 and 8 Hz and the humidity was controlled by flushing with dry nitrogen. The tests were continued for 8, 24 and 72 h at room temp. The total vertical displacement and the friction coeff. were measured continuously and sampled. Various addnl. measurements were performed after each test and the worn surfaces were obsd. microscopically. It was concluded that the a-b composites show less wear than the single-phase a- and b-Sialons. It was also concluded that the amt. of wear increases approx. linearly with increasing load and increases significantly more than linearly with increasing frequency. A wear mechanism was derived incorporating the measured data and the observations. [on SciFinder (R)

Sintergedrag en eigenschappen van β'-Si3Al3O3N5 keramiek

Het artikel is een samenvatting van een proefschrift verdedigd aan de T.U. Eindhoven. Het beschrijft het onderzoek naar het sintergedrag en de eigenschappen van P-SiJAb 0 3NS keramiek. Orie productiemethoden zijn geoptimaliseerd waarbij Ce02 en CaO als sinterhulpmiddel zijn toegepast. De invloed van procesparameters (gassnelheid en pelletdiameter) op de carbothermische productie van sialon is onderzocht. De kamertemperatuur-eigenschappen van de verschillende sialons bleken nauwelijks afhankelijk van de productiemethode en samenstelling

Isotherme weerstandsmetingen aan Fe40Ni40B20 en Pd80Si20

Technische MateriaalwetenschappenApplied Science

Hot pressing of sialon

Abstract in article

Reaction sintering behaviour and properties of β'-Si3Al3O3N5

The influence of additives on the sintering behaviour and properties of ß'-slalon is studied . Ce02 and CaO are used as sintering alds (1, 3 and 5 wt%). The ß'-slalon samples are prepared by reaction sintering tablets of Si3N4, Al3O3 and AIN in a gas pressure sintering furnace. The sintering conditions are optlmized by variatlon of temperature and time in a two-step-sintering process. The products are characterlzed by density, microstructure and hardness measurements

Microstructure and mechanical properties of β'-Si3Al3O3N5 ceramics

The properties of 21 different ceramics of ß'-Si3Al3O3N5 were measured. The sialons were prepared by three methods: reaction sintering in a gas pressure sintering furnace, reaction hot-pressing and sintering of sialon powder produced by carbothermal reaction from kaolin. Furthermore, the series differed in kind (CeO2 or CaO) and concentration of additive and process conditions. The quantities measured were composition (X-ray diffraction), density, microstructure, Vickers hardness (2 N), Young's modulus, Poisson's ratio, fracture toughness (SEN B) and biaxial strength. Generally the room temperature properties were hardly influenced by the production route, composition or process conditions. Fracture toughness and bi-axial strength were most sensitive to the process conditions. The mechanical properties of kaolin-derived sialon appeared to be as good as those of the other sialons

The influence of process parameters and starting composition on the carbothermal production of sialon

The ß-sialons (Si6-z Al z O z N8-z ) can be produced by carbothermal reduction of kaolin. The reaction mechanism of the sialon formation has been studied by several methods. Firstly, the composition of the reaction product is determined by XRD as function of the reaction time at 1400 and 1 500º C. The influence of additives, pellet size, nitrogen flow and clay type on the reaction is studied. Secondly, the carbon monoxide leaving the furnace is monitored. By studying the changes in carbon monoxide output as a function of the above-mentioned parameters a better understanding of the reaction mechanism has been obtained