Redistributional Preferences and Imposed Institutions

The 1980s saw an exploration of a variety of ways to use ethnography to study scientists. From the sociology of scientific knowledge, to actor-network theory to the ontological turn, science studies scholars increasingly shifted their focus from studying scientists to investigating scientific practices. This allowed them to inquire into what the objects of science are, instead of only inquiring into the people researching them. Following this shift, I have researched what superconductivity is in practice. The answer is: different things in different situations. In different experiments superconductivity is a different thing. However, these different instantiations of superconductivity are not separate versions. Some of the different instantiations need each other to work in practice. Following Annemarie Mol, I suggest that superconductivity is a 'multiple' object: it has more than one instantiation in practice, but it has less than many different versions. We might imagine superconductivity in practice to look like a network of different experiments in which it is given shape. Finally, I draw some conclusions of the 'multiplicity' of scientific objects for objectivity. I suggest that we move away from correctly representing reality, to presenting new ways of knowing and being. Which presentations are desirable depends on the values of an epistemic community

Series production of thixoformed steel parts

peer reviewedIn recent years several attempts were made to transfer the thixoforming technology of steel parts into industrial applicable processes. This paper gives an overview about the progress of a European consortium that established a fully automated thixoforming process for the series production of automotive steel parts. Due to the multi-faceted nature of this technology, problems concerning the development of suitable steel grades and tool materials as well as the development and application of an inductive heating system, a handling unit and of a complex forming tool had to be solved. Besides the development of adapted steel grades and the inductive heating, the handling of the semi solid billets plays a special role because during the manipulation of the parts from the heating station into the tool a loss of heat is unavoidable. Furthermore, scaling of the parts must be prevented. By means of a fully automated process line existing constraints were reduced and the forming process is kept reproducible. Improved silicon nitride composites have been developed as a tool material, which show good mechanical properties in combination with an acceptable chemical stability at the occurring process temperatures as well as in contact with semi solid steel. Basing on the practical experience a comparison of the thixoforming technology to existing processes and an outlook for the ftiture are, given