SURFTERM - Thermal stability of white layers intended as process-induced functional surfaces

Reference number 2018-04319
Coordinator CHALMERS TEKNISKA HÖGSKOLA AKTIEBOLAG - Department of Industrial and Materials Science
Funding from Vinnova SEK 500 000
Project duration November 2018 - November 2019
Status Ongoing
Venture Banbrytande idéer inom industriell utveckling
Call Banbrytande idéer inom industriell utveckling 2018

Purpose and goal

White layers induced during hard turning can be regarded as process-induced functional surfaces as they can provide improved wear resistance and produce compressive residual stresses which may significantly increase the component’s fatigue life. For them to have industrial relevance as process-induced functional coatings, the white layers would have to endure elevated temperatures as most applications would induce them. Thermal stability is therefore a fundamental materials issue for white layers and the investigation is the prime task in this project.

Expected results and effects

When confirming the applicability of mechanically-induced white layers as process-induced surface layers despite their nanocrystalline microstructure (sufficient thermal stability), they can be applied as functional coatings in a broad range of applications. Hence, the project has important commercial implications in sectors like automotive, aerospace, wind, marine, metal producing applications, any machine applications and/or any application that requires high wear resistance and/or increased fatigue and tensile strength.

Planned approach and implementation

SEM and TEM characterization will be used to assess the usability of mechanically-induced white layers as process-induced surface layers. In-situ TEM annealing will be performed on selected samples to monitor the microstructural development of the nanostructure at elevated temperatures. The elemental distribution of alloying elements will be investigated by use of SEM/TEM and atom probe analysis. To enhance thermal stability of mechanically-induced white layers further, work with computational materials engineering will be initiated.

The project description has been provided by the project members themselves and the text has not been examined by our editors.