Päivi Kivikytö-Reponen

Effect of test parameters on large particle high speed slurry erosion testing

Abstract A high speed slurry-pot wear tester was developed for close-to-reality heavy-duty wear testing of materials used in mineral applications. The samples are attached on four levels in a pin mill configuration. The tester and the developed sample rotation test method deliver reproducible results. This study focuses on the effects of testing parameters in large particle slurry testing. Parameters such as the speed, particle size and slurry concentration were varied. The effect of test duration was also examined. Round steel samples and slurry of water and granite gravel were used for testing. The test parameter variations were 4 to 10 mm for particle size, up to 23 wt-% for concentration and up to 20 m s−1 for the sample tip speed. The relationships between the parameters are discussed. The kinetic energy of the large abrasive particles is also considered. Wear surfaces studied with optical and electron microscopy are also presented and discussed.

Effects of Strain and Strain Rate on the Abrasive Wear Behavior of High Manganese Austenitic Steel

An abrasive wear analysis of the hardened surface layer in high austenitic manganese steel is presented to determine the effects of plastic strain and strain rate. The pre-deformation levels used in this study represent the typical surface layers resulting from the abrasive contact of Hadfield type steels. The effect of dynamic loading used in the pre-straining is accounted for alongside with various plastic strain levels. A friction study of the surface was included to determine the localization of work hardening and the ability of the microstructure to resist abrasion.

Modelling and testing of elastomer impact deformation under high strain rates

Abstract Elastomers are frequently used in applications involving repeated impacts of hard abrasive particles on surfaces at high or moderate strain rates. Operational conditions of components experiencing erosive and impact type wear are sometimes difficult to mimic in laboratory conditions, and as such, it is common to approach behaviour and lifetime predictions by meticulously studying different types of single impacts. This is particularly true for characterising and modelling of high strain rate impact events between hard particles and a wearing elastomer surface. This work presents and applies such a methodology for two specific elastomer materials: a natural rubber (NR) and styrene–butadiene rubber (SBR) compounds. The elastomer materials are subjected to quasistatic and dynamic testing conditions for determination of hyper- and viscoelastic material properties. The results are used in an iterative calibration procedure for establishing related constitutive models by applying the Ogden and Prony series models.

Tribological Testing and Modeling of Elastomeric Materials

In applications which experience repeated impacts by hard abrasive particles at high or moderate strain rates, elastomers are commonly used. The goal of the current work is to develop a methodology involving scratch testing and modeling which would be simple and cost effective for capturing the failure and wear behavior of elastomeric materials. The high failure strains as well as the extremely good wear resistance of elastomers make this task a formidable challenge. Modeling of a scratch test, however, seems to be promising in this regard.