For a safe design of micromechanical components, a reliable database of their properties is required. The existing material properties of macroscopic specimens normally cannot be used due to the neglect of some important aspects of the ''micro world'', e.g. the ratio of surface to volume is much higher which results in a larger influence of surface defects on the material strength. Detailed analysis of the microstructure and surface topography of microcomponents in combination with their mechanical properties is very expedient for straight-forward optimization of the manufacturing process. Using the resulting data of the properties investigated, correlations between production process, states and mechanical properties of the micro bending specimens made of ZrO 2 using low-pressure injection molding were identified. These correlations will be used to established a concept for dimensioning of mechanically loaded microparts.

For a safe design of micromechanical components reliable data of mechanical properties at static and cyclic loadings are of vital interest. Such data together with a detailed analysis of the microstructure are also useful for a straight forward optimization of the manufacturing process. Therefore, in the present study the mechanical behavior of microcast Stabilor-G Ò microspecimens under quasistatic and cyclic loadings and of slip cast and micro powder injection molded ZrO 2 microspecimens under quasistatic loadings was determined. Together with a microscopic characterization of the specimens it could be shown that the elastic-plastic behavior of Stabilor-G Ò microspecimens is strongly determined by grain anisotropy. In fatigue tests cyclic hardening occurs. The scatter of the lifetimes is not larger than observed at cast macrospecimens. The failure behavior of ZrO 2 microspecimens under quasistatic bending is mainly determined by surface roughness and near surface porosities as well as by the edge geometry. The highest characteristic bending strength which currently can be reached is nearly 3,200 Mpa.

No abstract

Analysis of the residual stress state, the microstructure and surface topography of ceramic microcomponents made of Y2O3-stabilized ZrO2 produced by micro powder injection moulding were performed. During the production of the microspecimens sintering conditions were varied. The measurement of residual stresses has been carried out using the MAXIM (MAterials XRay IMaging) diffractometer at HASYLAB beamline G3 at DESY in Hamburg (Germany). The microstructure and surface topography of differently moulded specimens were examined using a scanning electron microscope (SEM) and a confocal white light microscope type NANOFOCUS. The findings are used to establish correlations between process parameters and characteristics of the microcomponents. These will allow to improve the production process with respect to the mechanical properties of the microcomponents.

No abstract