Three-dimensional printing is a useful and common process in additive manufacturing nowadays. The advantage of additive polymer technology is its rapidity and design freedom. Polymer materials’ mechanical properties depend on the process parameters and the chemical composition of the polymer used. Mechanical properties are very important in product applicability. The mechanical properties of polymers can be enhanced by heat treatment. Additive-manufactured PLA’s mechanical properties and structure can be modified via heat treatment after the 3D printing process. The goal of this research was to test the effect of heat treatment on the mechanical and structural parameters of additive-manufactured PLA. This was achieved via the FDM processing of standard PLA tensile test specimens with longitudinal and vertical printing orientations. After printing, the test specimens were heat-treated at 55 °C, 65 °C and 80 °C for 5 h and after being held at 20 °C for 15 h. The printed and heat-treated specimens were tested using tensile tests and microscopy. Based on the test results, we can conclude that the optimal heat treatment process temperature was 65 °C for 5 h. Under the heat treatment, the test specimens did not show any deformation, the tensile strength increased by 35% and the porosity of the PLA structure decreased.

The surface modification is a suitable technology to increase the surface wear resistance of steels. In this way, the used substrate metal can be a low alloyed, cost-effective chemical composition steel. After the substrate metal heat treating, hardening and annealing, it needs surface modification. It well knew some surface heat treating technologies, like carburizing, nitridation, nitrocarburizing, and surface quenching. The surface coating is also very useful technologies when by the chemical or physical process it built a new layer on the surface. In this work, we compare different modification processes results made by the way of the traditional and new technologies advantages. The chemical composition and the structure determine the surface mechanically and wear resistance properties. The available chemical composition determines the surface modification technology [1-3]. It was prepared with different surface layers on the same substrate steel by a different process and inspected by different testing methods. On the base of the tests results needs to specification a new surface modification process for the high-level surface resistance layer.

Building protection on our century is very important because of the terrorist attacks. The old buildings in Europe aren’t enough strong again blast loads. Nowadays we know many different explosives and theirs effects of walls and human bodies. The detonation caused blast effect provokes building damage and fragmentation effects. The explosion caused damages, parts of bricks and fragments produce other secondary damage in other buildings and human bodies.It can’t protect the historical and old buildings by new walls and fences because of the cityscape. It needs to find new possibilities to improve the buildings resistance again blast effects. It needs a effectively thin and strong materials to reinforced the buildings walls. The new materials innovated by material science can be good solution for this project. These materials usually composites likes syntactic foams, spherical shells or carbon fields reinforced composites.