Essay Final Project 4

Submitted By sam624
Words: 7559
Pages: 31

Department of Engineering and Mathematics

Yizhou Zheng b2038773 BEng Mechanical and Automotive Engineering

Investigation into new materials for Vehicle's Axle Shafts to Enhance the Fatigue Life Cycles
Dissertation submitted in partial fulfilment of the requirements of the degree of of Engineering

Preface
This report describes project work carried within the Engineering Programme at Sheffield Hallam University between October 2013 and June 2014. The submission of the report is in accordance with the requirements for the award of the degree of “Bachelor of Mechanical and Automotive Engineering with Honours” under the auspices of the University.

Acknowledgements

Thanks are due to my project supervisor Dr. Ansari Imtiyaz for his guidance and support, and to Dr. Quanshun Lou of Secondary supervisor, for ensuring that the project did not stray too far from its aim. I would also like to thank Kitchen Matthew for their support and willingness to training preparation and Heat-treatment experiment.

Abstract
Materials' failure happened every year, it costs loss of economy and threatens people's safety. In automotive filed, vehicle have been driving since it was invented. Axle shafts in vehicle are undertaking a role of supporter, which withstand fatigue and fracture's happening. This project is aimed to investigate which one of heat treatments is more efficient to improve steel's strength in order to apply it to modern automotive industries.
There are five heat treatments are applied to six samples, and one of them is defined as control sample. Different heat treatments caused diverse changes inside of samples, by means of SEM and EDX machine to see how differences happened on surface of samples and inside elements.
XRD technology can help to measure what changed of crystalline structure inside of steel. To produce a graph of intense versus 2 theta that make a qualitative and quantitive analysis to crystalline structure.
Using Vickers 30 kg to make a hardness test. Comparing data collected from XRD with hardness test to analyse which effects of samples' heat treatment is most efficient to improve steel's strength, due to high strength can enhance the fatigue life cycles.

Contents
Preface 2
Acknowledgements 3
Abstract 3
Contents 4
Nomenclature 4
1. Introduction 4
1.1 Aims 4
1.2 Objectives 5
2. Relevant Theory and Analysis 5
2.1 Engineering Material 5
2.2 Microstructure in steels 14
2.3 Heat Treatment 19
2.4 SEM 20
2.5 EDX 20
2.6 XRD 20
2.6.1 Bragg's Law 21
3. Approach 21
3.1 Preparation 21
3.2 Heat Treatment 27
3.3 Preparation for SEM work 31
3.4 SEM (Scanning Electron Microscope) and EDX 34
3.4.1 Etching 36
3.5 XRD 36
3.6 Hardness test 37
4. Results 37
4.1 SEM 37
4.1 .1SEM on 24 March, 2014 37
4.1.2 SEM on 7 April, 2014 40
4.2 EDX (Energy Dispersive X-Ray Detector) 44
4.2.1 EDX on 24 March, 2014 44
EDX on 7 April, 2014 56
4.4 X-Ray Diffraction 65
4.5 Hardness test data 73
Control Sample 73
Sample 2 - Oil Quenched 73
Sample 3- Air Cooling 73
Sample 4 - Annealed 74
Sample 5 - Oil Quench - 200 DegC 74
Sample 6 - Oil Quench - 400 DegC 74
5. Discussion of Results 74
Discussion of SEM on 24 March, 2014 74
Discussion of SEM on 7 April, 2014 75
6. Critique 76
7. Costings 77
Conclusions & Further Work 77
Reference: 77
Appendices 78

List of Figures:

Figure 1- Tensile loads on rod 11
Figure 2 - Compressive loads on rod 12
Figure 3 shear strength on beams 13
Figure 4 - toughness is shown on the beam 13
Figure 5 - Elastic extension after applying the loads 14
Figure 6 - Plasticity shown after bending force 15
Figure 7 - ductility occurred when rod being drawn 15
Figure 8 - Applying compressive force to deform materials before them fracture occurs 16
Figure 9 - Two materials show different hardness 16
Figure 10 - two different loads cause different results due to different rigidity in materials 17
Figure 11- the formation and growth of voids during tension 19
Figure 12 -…