The purpose of this paper was to determine the mechanical properties of a Ti-6Al-4V titanium alloy produced by traditional CIP (Cold Isostatic Pressing) and by LENS (Laser Engineered Net Shaping), an additive manufacturing process. A reference material, being a commercial Ti-6Al-4V alloy, was also tested. The strength test specimens were produced from a high-quality, Grade 5 titanium powder. Each specimen had its density, porosity, and hardness determined. Compression curves were plotted for the tested materials from the strength test results with static and dynamic loads. These tests were performed on an UTS (Universal Testing Machine) and an SHPB (Split Hopkinson Pressure Bar) stand. The test results obtained led to the conclusion that the titanium alloy produced by CIP had lower strength performance parameters than its commercially-sourced counterpart. The LENS-produced specimens outperformed the commercially-sourced alloy both in static and dynamic load conditions.

During high rates of fire, the bore of the firearm barrel is exposed to high temperatures. This exposure induces structural changes in the barrel material, which is especially significant for the substrate of the galvanic chrome plating. The alloy steel grades used currently for firearm barrels, when exposed to heating above the ferrite stability limits, develop a phase transition with a discrete negative change in the material volume, which results in typical crazing in the bore. This effect is destructive to the galvanic chrome plating, leading to a loss of adhesion, which reduces the ballistic performance of the firearm, especially its muzzle velocity. This can be prevented by manufacturing barrels from steels having a limited range of phase transitions. The primary method for determining the presence of distinct volume changes in steel due to phase transition is dilatometry over a wide temperature range, which includes the interval within which the barrel bore is heated. This paper presents the dilatometry results for four steel grades, which included a steel grade currently used for firearm barrels, and an analysis of the effects of phase transition on the degradation of the barrel bore.

The paper presents the results of reconstruction of selected gun elements with application of 3D scanning technology. Algorithm of under investigation process, the way of preparing object for scanning and measuring process were also presented. This article discusses also data acquisition of clouds of points and methods of some activities with measured geometry data (i.e. solving some imperfections caused by the preparation or by the measurement process). Geometry was remeshed by the creating a new mesh of polygons to unify shapes defined after previous steps. On the basis of cloud of points measurements, the solid geometry of the whole object was prepared. The effect proved satisfactory accuracy of the estimated parts’ characteristics and allowed for recommendation of the mentioned approach in the described process.

The aim of this paper is to present the results of experimental investigations concerning a mechanical response of 2D regular cellular structures with different topologies in an aspect of crashworthiness behaviour. Developed by the authors, genuine topologies of 2D regular cellular structures were built with using Fused Deposition Modelling (FDM) additive manufacturing method and afterwards they were subjected to uniaxial compression tests. A wide range of structure topologies made from three commercially available polymeric materials ABSplus, Nylon12 and PC-10 were examined during carried out investigations. One of the commercially available CAD systems was used to define proposed structure topologies. It was found that the energy absorption depends on the elasticity of a structure, where high strength geometries represent linear crashworthiness behaviour with bending and cracking while flexible ones present exponential increase of deformation force due to densification of the structure.

The purpose of the paper is to present a research methodology used in order to predict the mechanical response of additive manufactured regular cellular structures subjected to quasistatic loading conditions. The authors’ attention was focused on a numerical approach. The proposed method of investigation allows estimating crashworthiness behaviour of regular cellular structures under loading boundary conditions of uniaxial compression. The applied methodology is based on finite element analyses using an implicit solution. During the numerical analyses, selected topologies of 2D cellular structures were investigated. The validation based on correlation between numerical and experimental results was performed at the final stage.

With the advent of modern hostage rescue tactics and new training shooting methods, the military and police agencies of many countries began to look for technical ways to minimize overpenetration risks and to reduce lead contamination hazards on firing ranges. One widely-accepted solution is pistol ammunition containing frangible bullets. Frangible rounds usually made from free lead matrix composite are designed to break apart into small pieces when they hit walls or other hard surfaces to prevent ricochets during close-quarters combat or training shooting. This behavior of frangible bullets maximizes the round's transfer of energy to the object and minimizes the chances that pieces of the bullet will exit the object at dangerous velocities. In this paper, we propose to use the metal-ceramic composite made from the 90% Cu + 5% WO3 + 5% Al powder mixture as a material on 9 mm frangible round. The preliminary technological process of frangible bullets material manufacturing was developed to obtain metal-ceramic composite containing an Al2O3 matrix. The developed technological process is based on the powder metallurgy in which the phenomenon of ceramic matrix separation is used during the sintering operation. The results of technological and ballistic investigations with frangible metal-ceramic bullets are reported in our work. Besides with a view to exothermal character of chemical reactions during sintering operation, the results of influence of reaction heat on sintering temperature is presented. Generally it was found that metal-ceramic bullets have sufficient strength to withstand the firing operation without breaking up in the barrel of the gun or in flight up to the target. Furthermore, thanks to ceramic phase, developed bullets break up into very small pieces upon impact with a hard steel plate.