Microstructure analysis and Hardness of Al C355.0 with step varying weight of Hematite particulate reinforcement

T.R. Rajesh¹*, B. Venkatanarayan², S.K. Vutukuru³ and B. Prabhakar Kammar⁴

¹Visvesvaraya Technological University-Jnana Sangama, Department of Mechanical Engineering, Research scholar, Belgaum, IN590018 Karnataka, India
²South East Asia College of Engineering and Technology, Department of Mechanical Engineering, Ekta Nagar, Basavannapura, K.R.Puram, Bangalore, IN560049 Karnataka, India
³MVJ College of Engineering, Department Of Aerospace Engineering, Near ITPB, whitefield, Bangalore, IN560067 Karnataka, India
⁴Gopalan College of engineering and Management , Department of Mechanical Engineering, Seetharam Palya, Basavanagar, Bangalore, IN560048 Karnataka, India
*Correspondence: rajeshtrgcem@gmail.com

Abstract:

A detail study on the microstructure of engineered Al C355.0 metal matrix with step varying weight of hematite particulate reinforcement from 0–12% in the step of 3% by using stir casting method in the copper chills with and without water circulation is carried out in the present work. It was earlier realized that copper chills increase the hardness of metal matrix compared to its base alloy. The novelty lies in the circulation of water during solidification process so that a stronger matrix reinforcement bonding, low cluster regions, grain reinfinement with minimum porosity could be achieved. The maximum hematite particulate size was 150 μm. From the Scanning Electron microscope, it is clear that there was good distribution of reinforcement in the matrix but not exactly clear whether it is uniform or non-uniformly distributed. SEM and XRD analysis results show the presence of hematite in the matrix. With increase in reinforcement the hardness increased up to 9% of the reinforcement and then decreased. It is concluded that water circulation on casted composites have good effect in improving the hardness of the Al C355.0 at 9% of hematite resulting to BHN 128 and without water circulation it was found to be BHN 124. It is realized that water circulation improves the hardness of the composite for all the cases with hematite as particulate reinforcement for Al C355.0.

Key words:

copper chills, hematite, microstructure., water circulation

Evaluation of friction force using a rubber wheel instrument

R. Chotěborský¹,* and M. Linda²

¹Department of Material Science and Manufacturing Technology, Faculty of Engineering, Czech University of Life Sciences, Kamýcká 129, 6521 Prague 6, Czech Republic; *Correspondence: choteborsky@tf.czu.cz 2 Department of Electrical Engineering and Automation, Faculty of Engineering, Czech University of Life Sciences, Kamýcká 129, 16521 Prague 6, Czech Republic

Abstract:

Abrasive wear is the most important process for innovation of new materials in agriculture. The method depends on the internal (the microstructure of the abraded material) and external (characteristic of the abrasive particle, force, etc.) conditions. A modified rubber wheel instrument based on the ASTM G65 procedure was used to obtain the study results. The results showed that the friction between an abrasive particle and abraded material was influenced by the microstructure of the abraded material and this relationship can be used for abrasive wear evaluation. The study result also showed that the limitation of using the rubber wheel method was the natural frequency of the system. In this study, the natural frequency was found to be 200 Hz, which is useful for elimination of the algorithm for frequency and amplitude during wear analysis.

Key words: