Micro Indenter
The 30 N high load head greatly expands the capability of the NanoTest Vantage to cover both the nano and micro ranges. Both loading mechanisms are permanently mounted side-by-side, allowing easy transfer of the sample between both.
Materials commonly tested including cemented carbides, metals, shape memory alloys and hard coatings.
The Micro Indenter can be used for:
- Micro-indentation, micro-hardness
- Micro-impact and fatigue
- Micro scratch and wear
- These tests can be done at high temperature (max 500°C) or in inert environments.
- The optical microscope can be used for precise positioning of indentations.
Micro-indentation example: Cemented carbides
A knowledge of both hardness and toughness is required to assess performance under severe mechanical loading. Even subtle changes to the % binder and carbide grain size in cemented carbides can have a dramatic influence on tool life. It is the sub-surface mechanical properties that control the fatigue performance in applications such as high performance stamping. Micro-Indentation is used to determine the mechanical properties of different cemented carbides.
Figure 1 shows the variation in plasticity index with load for three commercial grades of WC-Co. Plasticity index = plastic work/total work. Even small changes can dramatically influence tool life.
Figure 2 shows the high load stamping wear of WC-Co tools. There is a clear direct correlation between the Micro-Indentation data and the tool life. The WC-Co with the lowest plasticity index has greater tool wear due to brittle cracking.