Public defence in Mechanical Engineering, M.Sc. Nurul Anwar

Towards more sustainable sand casting

Sand casting is one of the oldest metal-forming techniques known to humans. Today, sand casting is playing a major role in the manufacturing of many different metal products, ranging from engine components, bearings, valves, pump bodies, windmill rotor hubs etc. It offers economical production of a wide range of alloys and sizes of components. As a summary, the process includes pouring molten metal into a sand mold which has a cavity conforming to the shape of the product and after the metal has solidified, the raw casting can be taken out. Sand molds are made using sand, binder and different additives. One concurrent concern is the use of widely used organic binders which breakdown at elevated temperatures to give off harmful emissions. These are bad for human health, causing odor in the facilities and can lead to gas defects in castings. Additionally, although silica is the most widely used sand for sand casting, alternatives are sought for various reasons like worker health safety, increased scrutiny for silica sand mining etc.

This has led to a reemergence in the interest in inorganic binder systems which do not give off harmful emissions at high temperatures. However, foundries considering a switch need more information how different inorganic binders compare to that of organic binders, and how these perform in terms of mold and cast quality. This dissertation focuses on different sand and binder combinations, culminating in more thorough testing of ferrous casting using inorganic molds. Results from the dissertation aims to facilitate the choice of mold materials with a more extensive outlook into their characteristics through a series of sand, mold and casting quality test. Examples of these include sand property tests, mold strength tests, loss on ignition tests, gas emission tests, SEM imaging of binder bridges, metrological analysis of patterns, molds and casts. Apart from the conventionally used inorganic binders in liquid form, a solid version of inorganic binder was studied in detail and efforts were directed at improving it which has the potential of simplifying 3D printing of sand molds and to be the sustainable mainline foundry binder for sand casting.

Doctoral Student: Nurul Anwar

Opponent: Prof. Rafal Danko, AGH University of Krakow, Poland

Custos: Prof. Juhani Orkas, Aalto University School of Engineering, Department of Mechanical Engineering

The public defense will be organized in Lecture Hall 216, Otakaari 4 and online on Zoom.

The thesis is publicly displayed 10 days prior to the defense in the publication archive Aaltodoc of Aalto University. 

Contact information of doctoral student:

Doctoral theses in the School of Engineering: https://aaltodoc.aalto.fi/handle/123456789/49