Understanding the surface properties
From water droplet erosion to environmental corrosion, understanding what alters the surface properties of a material and how it performs in harsh environments is critical to lifetime management, failure analysis and confidence in the selection of materials for fit-for-purpose products and components.
The surface of a material can be altered by factors such as water, dust, extremes in temperature, mechanical contacts, chemicals and mechanical loading. The techniques are applied to both bulk surfaces and increasingly to advanced coatings deposited on at the surface to increase wear or erosion resistance or reduce friction. We offer a range of testing services and consultancy that can be tailored to your specific needs.
Sliding and reciprocating wear, friction and abrasion
The performance of many products and engineering components depends critically on the wear and friction caused by movement in contacting surfaces. Abrasion occurs when small hard contaminant particles get between the contacting surfaces and cause scratches or gouges. Our activities are focused on developing methods that will help UK industry to evaluate and solve their friction and wear problems, understanding the mechanisms causing damage, improve the performance of thin coatings and to enable them to develop solutions though a robust testing strategy.
Damage to moving or rotating components from solid particles and water droplets can be catastrophic in high speed applications. NPL has unique facilities for controlled testing of water droplet erosion and solid particle erosion at high speeds and high temperatures. These test apparatus, in conjunction with our microscope facilities, can determine the durability of a surface or coating.
NPL has a long history in the development of measurement techniques for nano-scale instrumented indentation. Much of the underpinning work that underlies the new ISO standards for instrumented indentation was developed through EU projects where NPL was a major partner or coordinator. We have a range of complimentary nanoindentation apparatus which operate under different conditions, including the ability to operate within an SEM so that the measurement process and material response can be seen. Using our ion beam milling facilities micro beam bending, pillar and powder particle crushing can be carried out. Our current work is extending the temperature range of nanoindentation instruments to provide data more applicable to operating conditions, improving the analysis of ion beam milled cantilevers and pillars and improving measurements at different length scales to meet the needs of the latest advanced manufacturing processes.