Compressive properties of cell structures manufactured by photo-curing technology liquid polymer resins – Polyjet Matrix

The article presents the results of compressive strength tests of cylindrical samples with a hexagonal cell structure. The samples were made of MED 610 material using the photo-curing technology liquid polymer resins. The compressive strength was estimated on the basis of a static compression test of the printed elements. It has been shown that the PolyJet Matrix 3D printing technology enables the printing models with a thin-walled cell structure, which, while maintaining the appropriate strength properties, can be used in the design and production of certain utility models.

Stress relaxation in samples made of acrylonitrile butadiene styrene material manufactured by fused deposition modelling

Increased interest in fused deposition modeling (FDM) resulting, for example, from its use in the production of utility models determines the undertaking of research on mechanical and rheological properties of materials. Mechanical and rheological properties of models made of materials used in FDM technology depend on technological parameters. In this paper, the effect of 0° and 90° print orientation on stress relaxation was analyzed. Additionally, the usefulness of the rheological model to describe the relaxation curve was evaluated. Stress relaxation tests were performed by tensile testing. The five-parameter Maxwell-Wiechert model was used to describe stress relaxation. The tests showed little effect of print orientation on the rheological parameters of the five-parameter model. The Maxwell-Wiechert model showed a very good approximation to the stress relaxation curves.

Development in broaching technology. Part I. Development of broaching machines and tooling devices

The paper structured into three parts outlines the present state of the broaching technology. The first part highlights possible process variants for internal and external operations and designs of broaching machines as well as CNC control systems and other advanced automatization forms. The second part will be devoted to the progressive broaching methods such as rotary broaching, hard broaching and MQL application. The third part will discuss some important directions of experimental investigations carrying out for more efficient and reliable broaching processes.