Master Thesis: Residual Stress Measurements in Automotive Gear Fillets Using X-Ray Diffraction

30 hp – Residual Stress Measurements in Automotive Gear Fillets Using X-Ray Diffraction: Sensitivity Analysis 
 

Background  
Residual stresses introduced during manufacturing processes play an important role in the performance and durability of automotive transmission parts. For this reason, accurate residual stress measurement in critical areas is of highest importance. 

X ray diffraction (XRD) is a common method used to evaluate residual stresses. Measurements in complex geometries have been limited by the size of the measurement area, the accuracy of the position of measurement, and other factors.  

Traton Materials Technology recently purchased an equipment that offers an accurate position of the measurement and a small measurement area, giving us the possibility to measure in complex geometries. 

Objective  

The objective of this master's thesis is to investigate the sensitivity of XRD-based residual stress measurements to different experimental and sample-preparation parameters when measuring residual stress profiles in gear tooth fillet. 

The thesis will investigate how factors such as cutting/sample preparation, electropolishing, and measurement position can influence the measured residual stress profile. Particular attention will be given to the challenges associated with obtaining consistent and repeatable measurements in the gear fillet. 

Job description  

The thesis will include: 

• Planning and performing experimental residual stress measurements using XRD. 

• Investigating the influence of different sample preparation and measurement parameters on the residual stress measurements. 

• Investigating the influence of electropolishing parameters and material removal by confocal microscopy. 

• Evaluating the repeatability of electropolishing and residual stress measurements. 

• Comparison of measured residual stress with existing simulation results. 

The exact experimental parameters and scope will be refined during the project based on the initial results and available project time. 

Expected outcomes: The primary outcome of the thesis will be a sensitivity analysis of XRD residual stress measurements in the gear tooth fillet. The study is expected to identify which experimental and sample-preparation parameters have the greatest influence on the measured residual stress profile and to quantify the significance of these effects where possible. 

What you will gain: This thesis offers the opportunity to work with real automotive transmission gears and address an industrially relevant measurement challenge. During the project, you will gain hands-on experience in XRD-based residual stress characterization, electropolishing and controlled material removal, experimental method adaptation and optimization, residual stress profile measurements, repeatability and experimental evaluation, and practical laboratory work and data analysis.