VŠB - Technical University of Ostrava Faculty of Materials Science and Technology
Department of non-ferrous metals, refining and recycling Academic year: 2019/2020 Name of head of diploma thesis: prof. Ing. Jaromír Drápala, CSc.
EVALUATION OF DIPLOMA THESIS
Time of the defence of diploma thesis:
30.6.2020
Title of diploma thesis:
Casting aluminum alloys for automotive
Name and surname of student:
José SENA
Theoretical part of the diploma thesis: Background research in the area of casting alloys on the basis of Al-Si and Al-Si- Mg; defects in aluminum alloys; influence of additives and admixtures on properties of aluminum alloys; casting technologies of aluminum alloys.
Practical part of the diploma thesis: Chemical analyses of aluminum alloys; SEM/EDX characterization of microstructure and chemical compositions of intermetallic phases in aluminum alloys; complex metallographical analyses of different types of aluminum alloys: macro- and microstructure (defects, porosity …); determination of the size and morphology of grains in etched aluminum alloys in polarized light; basic tests of mechanical properties, microhardness HV.
Diploma thesis contains: 60 pages, 24 references, 16 tables and 53 figures (graphs or photos).
In the theoretical parts of the thesis were discussed problems connected with characterization of various types of aluminum alloys, Al-Si and Al-Si-Mg systems, incl. influence of additive elements on properties and quality of Al alloys after casting. This part of the thesis was elaborated very well.
In the practical part of the thesis were studied three types of Al alloys: AlSi7Mg (3 samples), AlSi12 and AlSi10Mg after casting (2 samples) and AlSi0.7Mg after casting and forming (3 samples). For diagnostics of these alloys were used methods: Chemical analyses - optical emission spectrometry (OES), structural analyses – optical metallography (OM), incl. color etching, SEM/EDX analyses for determination of structure and composition of individual phases, microhardness measurements. The defects (porosity) in AlSi7Mg alloy and grain sizes in AlSi0.7Mg alloy were studied too.
The results from OM, SEM are presented in photos, results of x-ray analyses in tables. Each result was discussed individual. Three types of Alx(Fe,Mn)ySiz intermetallic compounds and one type of AlxSrySiz were found in samples.
José Sena used to work separately. Communication was only via e-mail correspondence (Covid-19). The obtained results incl. reach discussion has excelling level.
Assignment of diploma thesis was fulfilled in the theoretical and practical part completely. Some results are original.
I evaluate this diploma thesis as “excellent”.
Ostrava, 15 June 2020 prof. Ing. Jaromír Drápala, CSc.
