Abrasive Wear Tests
Overview of Abrasive Wear Tests
This Section aims to provide a general overview of abrasive wear test methods for evaluating wear characteristics of liner samples. Because there are many individual testing procedures, there is no claim to completeness. Instead, the principles are briefly explained, as well as several advantages and disadvantages of general test rig build ups are shown.
Particle On Disc Test
Test Principle:
The particle on disc test is transferred from the classical pin on disc test to determine abrasive wear characteristic of solids. A single particle is fixed to a special holder and a normal force acts on the particle. The disc consists of the liner sample material and rotates at a constant speed.
Advantages:
- Exactly defined sliding conditions between the particle and the disc
- Not standardized for usage of particles, but high correlation of the procedure to pin on disc standard, e.g. ASTM G99, DIN-50324
- Only a small amount of bulk material is needed (several particles, less than 1 kg)
Disadvantages:
- Fixed particle is representing less industrial application case due to no free interaction between particles and liner sample
- Preparation of the individual particle samples, including the suitable fixation to a holder can be very time consuming
- High number of individual experiments is necessary to obtain a representative wear coefficient for the entire bulk material
Dry Rubber Wheel Test
Test Principle:
The wheel has a rubber sheath and rotates with a constant velocity. The bulk material falls due to gravity from a funnel in the gap between the wheel and the liner sample. A normal force acts on the liner sample and press it against the rubber wheel and the bulk material inside the gap. The particles are pressed into the rubber and slide along the liner sample without rotation.
Advantages:
- Defined sliding conditions between the particle and the liner sample
- Standardized procedure according to ASTM G65
- Easy to handle in laboratory scale and small amount of bulk material required
Disadvantages:
- Pressed in particles representing less industrial application case due to no free interaction between particles and liner sample
- Limitation of the suitable bulk materials to fine grained materials with low particle size variation. The standard abrasive bulk material is sand
Abrasive Wear Pot Test
Test Principle:
One or more liner samples are fixed to the end of the rotor. The rotor in placed in a pot filled with bulk material, so that the samples are surrounded by bulk material. For the test the rotor rotates with a defined velocity. Furthermore, samples can be rotated to their own axis to determine different angles. There are also others in which a lid is seated on the bulk material. This can be acted upon with an additional force.
Advantages:
Relatively easy to prepare and use in laboratory scale
- Only a relatively small amount of bulk material is needed (several kilos)
- Standardised Procedure according to german VDI 4472 to mainly determine wear factor in compare to a reference liner sample
Disadvantages:
Superposition of different wear mechanism of sliding and impact wear are possible during testing
- No clear distinction between sliding and impact possible
- Relatively high wear of the bulk material or frequent change of the bulk material necessary
Linear Belt Wear Test
Test Principle: