Master thesis at Volvo Group Trucks Technology and Linköping Uni

Improving performance of high SiMo ductile iron by changing composition (30 ECTS)


High SiMo ductile iron is a standard material for exhaust components such as manifolds and turbocharger housings for heavy duty diesel engines. The exhaust manifolds are typically used at temperatures in excess of 700°C. Thermo-mechanical fatigue, oxidation and creep limit the use of this material in demanding truck applications. Are you interested in studying tensile strength, low cycle fatigue, oxidation, and creep resistance at elevated temperatures, then this master thesis is for you.


Suitable background


We seek a student with a mechanical engineering background, preferably in Material Science.

Description of thesis work
Background and aim

Ductile irons can exhibit very low elongation of less than 1% strain in the temperature range of 350° to 500°C. This phenomenon is referred to as elevated temperature or intermediate temperature brittleness. It has been proposed that this brittleness can be reduced if the material is cast with proper Mg/P ratio.
In this project, you will study high SiMo with 5% silicon and with proper Mg/P ratio. The reference material is high SiMo with the Mg/P ratio used normally.
Description

The main aim of this project is to study the mechanism causing this intermediate temperature brittleness, how can it be counteracted, what does it mean for high temperature low cycle fatigue and tensile tests. Evaluation of the oxidation and creep resistance of the high SiMo material is also included in this project.


The thesis work will include:
Literature review
Tensile testing at room temperature and elevated temperatures
Low Cycle Fatigue (LCF) testing at intermediate temperatures
Evaluation of oxidation and creep resistance at high temperatures
Studies of microstructure using SEM and optical microscopy

The Sehitoglu damage model is often applied for evaluation of thermomechanical fatigue (TMF) of components working at high temperatures. An aim within this project could be to identify the parameters from testing for the Sehitoglu damage model.


The project is a mix of theoretical and practical work and you will be a part or a creative environment with skilled and experiences colleagues at our well-equipped materials technology lab in Gothenburg and Linköping.


When and where?


Start of the thesis work is preferred in early 2023. A major part of the work is to be carried out at Linköping University. A small complementary part can be performed at Volvo Materials Technology in the Lundby area, Göteborg.


Thesis Level: Master


Language: English / Swedish


Starting date: February 2023


Number of students: 1 student


Tutor:
Maqsood Ahmad, maqsood.ahmad@volvo.com,
Viktor Norman (viktor.norman@liu.se)


Kindly note that due to GDPR, we will not accept applications via mail. Please use our career site.