• Using a 3D printer to innovate textile products

    pg(s) 139-141

    Today, 3D printing is available not only for industrial, semi-professional use, but also for hobbies and schools. Therefore, students TUL make full use of 3D printing within the subject Project Management. One of the topics they address is use of 3D printing for a textile product. They are looking for an answer to the question: How to 3d printing technology use for made a textile product?

  • Survey of process parameters for a better product quality in industrial production with a low-cost 3D printer

    pg(s) 135-138

    The most important areas of the industry, need products with short development stages. Additive manufacturing (AM) techniques, as Fused Deposition Modelling (FDM), are an integrated solution to the overall conception and product development cycles; the same competition is based on the development of new products with technological features, design and functional solutions in the shortest time. In this paper are discussed different process parameters for fused deposition modelling that affects the parts quality by using a low-cost 3D printer machine in order to produce an industrial product. The process parameters taken into the analysis, resulted effective in improving final parts quality.

  • Tribological Examinations of X210Cr12 Steel

    pg(s) 131-134

    In order to test the tribological properties of the high alloy ledeburite steel X210Cr12, test samples were made on which the mass loss was measured before and after the wear test. The test was performed using the “pin on disk” method on the Taber abraser device, with part of the samples tested without lubricant and part with lubricant to compare and present the results. X210Cr12 steel was chosen as the material for the pin sample, while low alloy steel was chosen for the disk sample. In the lubricant test, hemp oil was used and analyzed to show the effects of this oil on the lubrication and wear of the material. During the test, each sample was subjected to a modified load and a modified number of cycles. From the test results, it can be concluded that hemp oil exhibited satisfactory properties over all test cycles, with an approximately constant pattern of mass loss. In addition, hemp oil showed more favorable properties at higher test loads and a greater number of test cycles, so it can be used as a lubricant based on the test results obtained under test conditions such as those that prevailed in this test.

  • Obliteration of surface defects in 3D printing of metals by reactive electro spark surface modification

    pg(s) 126-130

    In this work the possibilities of reducing the roughness and defects of surfaces obtained by 3D printing with selective laser melting (SLM), via reactive electrospark surface modification (ESD) with low-melting AlSi alloys has been shown. The influence of the energy parameters of the ESD process on the roughness, microstructure, microhardness and performance characteristics of the coatings has been studied. Surfaces with new phases and ultrafine crystal-amorphous structure with particle sizes from micro to nano level, with new relief, with thickness up to 15 μm and microhardness up to 11 GPa were obtained, as the initial SLM roughness from Ra = 8-11μm is reduced to Ra=3-5 μm. Possibilities for control of the characteristics of the coatings and purposeful synthesis of new phases by changing the parameters of the spark discharge have been established. The parameters of the ESD process, which provide simultaneous reduction of SLM surface roughness, removal and erasure of the defects and targeted reactive synthesis of new phases with high performance properties and wear resistance, are defined and optimized.

  • SQL vs NoSQL databases from developer point of view

    pg(s) 95-97

    Application developers mostly must choose between two main categories of the database: SQL (Structured Query Language) and NoSQL (Not Only SQL) to build their solutions. SQL databases, also known as relational databases, have been in use for a very long time and despite their age, SQL databases remain extremely popular with developers. Six of the top 10 results on DB-Engines’ list of most popular DBMS are relational DBs (September 2021). In the meantime, NoSQL databases or non-relational databases, have gained popularity year after year. One of the most widely used NoSQL databases is MongoDB, ranked 5th on DB-Engines’ list. In this article, we will explore what are the differences between SQL and NoSQL, and which database to use for application development.

  • Reverse engineering in automotive design component

    pg(s) 62-65

    The paper presents the possibilities of using reverse engineering in the digitization of automotive components and their modification. A CAD model of the part was created based on the scanned point clouds. Subsequently, this model was compared with the original cloud points. The point clouds were scanned by a laser 3D scanner in PolyWorks software. The reference 3D model was created from a point cloud in the CATIA program. The comparison of the scanned point cloud and the reference model is performed in PolyWorks. The Check IMAlign project module is used for this. This module allows you to compare the scanned point cloud, it is merged from several scanned lines into one whole point cloud, which are created by a CAD model. The preparation of the 3D scanning arm FARO PLATINUM ARM and the process of scanning the prototype of the front fender of the car are described.

  • New concepts of severe plastic deformation combined processes

    pg(s) 59-61

    On the basis of review of last developed combined metal forming processes the new concepts of severe plastic deformation combined processes aimed at further improving the deformation performance are proposed. The presence in all three proposed variants of the ECAP scheme will allow deforming without significantly changing the initial dimensions of the workpiece.

  • Low power photovoltaic system implemented by means of flexible module

    pg(s) 54-58

    Paper deals with low power photovoltaic system implemented by means of flexible module. Flexible modules powered by sunlight are really a very interesting and promising novelty, being one of the newer alternative energy sources. A selected technical solution with specific characteristics of the individual components is presented. Measurements with digital measuring equipment were performed and experimental results were presented. In conclusion, it is summarized that the tested flexible module gives good results.

  • Design and 3D printing of holders for XRF analysis requiring small volumes of sample

    pg(s) 18-20

    The preparation of XRF tablets with small amounts of samples produced from various synthesis is a challenging operation. Zeolites and other types of samples with minimal volumes are frequently provided for analysis by X-ray fluorescence spectroscopy. Here we present three types of holders made of PLA (polylactic acid) using commercially available 3D printing technology. The employed material is a bioactive thermoplastic aliphatic polyester extracted from renewable resources and is biodegradable. The holders have reduced diameters of the measured area and can accommodate powders, sheets or solid state samples. The holders are basically three-dimensional plastic models that can be designed and printed based on the provided sample. They are low cost and can be easily applied in practice. The design of the first type of holders is targeting powder samples, allowing the reduction of the required amount from 5-10 g per sample to 1 g. The second type of holders aimed the XRF analyses of textile like materials while the third type of design aimed metal alloys. Examples of the use of the holders are the analyses of coins (here 2 leva is shown) and textile samples containing different metals (e.g. zinc).

  • Experimental analysis of creep behaviour of solder alloys at near eutectic point by using indentation test

    pg(s) 225-228

    Eutectic solder alloys are widely used in the microelectronics industry. The phenomenon of creep and its mechanisms are important aspects that influence the performance of solder alloys. During the last two decades, a Pb – solder alloys is fast becoming a reality in lead free electronic products due to harmful caused as toxic material to environment and health, international legislative pressure and marketing. The replacement of Sn – Pb alloys with Sn-Ag-Cu (SAC) alloys needs reliable results for assuring the usage of this solder joints material in electronic industry. In this paper has been studied the creep behaviour of a group of alloy in the system Sn-Ag-Cu (SAC) near the eutectic point. In this research work we have used three different alloy samples which are 95, 5Sn-3, 8Ag-0,7Cu, 96, 5Sn-3, 0Ag-0,5Cu and 95, 46Sn-3, 58Ag-0,96Cu. Indentation technique has been conducted to study the creep behaviour of these three SAC alloys by determining the creep parameters at different temperatures. The temperature used was at room temperature 30oC until 100oC and the stress used was 64MPa-178MPa for the indentation diameter 1 mm and 0.5 mm. The experimental method and results of the creep parameters like activation enthalpy Q, the stress exponent n of the power law model and the parameter of the material A were briefly described in this paper. From the creep curves, constructed for alloys and considered loads, the values of creep stress exponent n were determined for the stud ied alloys.