Advanced Configuration Parameters of Post Processor Influencing Tensile Testing PLA and Add-Mixtures in Polymer Matrix in the Process of FDM Technology

The present paper focuses on the configuration possibilities of post -processor influencing mechanical properties of a given test sample produced by the FDM printer from different materials. The research consists of assessing the composite material configurations through a static tensile test conducted on 80 samples produced. The samples were produced based on ISO 527-2 standard, type 1A, with a horizontal position and a layer height of 0.2 mm. The individual samples consisted of four basic groups of materials—the pure Polylactic acid (PLA) plastic (reference sample), and three composite samples with admixtures—PLA matrix with a copper admixture, PLA matrix with an iron admixture, and PLA matrix with a steel admixture. The static tensile test was conducted at a test speed of 5 mm/min. During the research, reference samples (pure PLA) were assessed in five orientations. Samples made of the PLA composite materials with admixtures were manufactured, tested, and evaluated only in the 0° orientation. The paper concludes by comparing the results of measurement with the original material, free from additives, and with the researched influence of the orientation of the prints on the resulting mechanical properties of shear samples and their surface structure. In the conducted experiments, the lowest tensile strength has been demonstrated in test samples the orbital transitions and the upper surface layers of which were parallel to the infill.

THE INFLUENCE OF INTERRUPTING THE BRAZING PROCESS OF HASTELLOY X SUPERALLOY ON THE PROPERTIES OF THE JOINT

In this paper, disruption of brazing process impact on behavior of filler metal and properties of the joint was investigated. Hastelloy X sheet samples were brazed using Ni-13Cr-4Fe-4Si-2,7B filler alloy. Two identical sets of samples were heated in high vacuum, once load reached specified temperature process was interrupted. Subsequently, one set of samples was tested and second set was subjected to rebrazing in proper time and temperature, dedicated for used filler material. Disruption of the process in following temperature was analyzed: 930, 960, 1050, 1127, 1145, 1170°C. After both processes macroscopic observations of joint, peel test, static tensile test and spreadability analysis were carried out.

Mechanical properties of carbon fiber reinforced polyamide produced by CFF method (Continuous Filament Fabrication)

The study presents the influence of content and orientation of continuous carbon fibers (CF) on the static tensile test results of a polyamide matrix (PA) composite, produced using Continuous Filament Fabrication (CFF) technology. Taking the polyamide’s crystalline structure into account, an attempt was also made to produce test specimens under various temperature conditions of the device chamber. The test samples were produced in use of the Mark Two device (Markforged, Great Britain). It has been shown that the content and orientation of the reinforcement in relation to the direction of stresses generated during the static tensile test, has a significant impact on the parameters determined in this test. The dependence presented in the article, confirms that materials in a thermoplastic matrix, reinforced with continuous fibers are a topic in line with the topic of current trends in fields of material engineering and design of structural products. The conducted research proves that the temperature in the working chamber of the Mark Two device affects formation of mechanical properties of PA+CF composites, fabricated using CFF technology. Manufacturing composites at elevated temperature resulted in significant decrease of E and Rm values for 4 out of five tests performed, but a considerable increase in their relative elongation at break was noticed.

Evaluation of measurement uncertainty in a static tensile test

This article presents a scheme of the procedure for assessing the measurement uncertainty of material constants determined in the static tensile test. The key analysis was preceded by a discussion of the concept of uncertainty of measurement, equated with absolute error, the concept of relative error and methods of assessment of these errors, depending on the type of mutual dependence of the analyzed quantity and the measured quantities. The next step in this article shows examples of stress–strain curves, which were used to calculate errors, as well as specific material constants. By importing the spreadsheets of the Mathcad package, which was used in the analysis, the procedure for assessing the measurement uncertainty was specified.

Effect of Changing the Parameters of the Multi Jet Fusion (MJF) Process on the Spatial Objects Produced

This paper describes the principle of operation of Multi Jet Fusion (MFJ) technology in detail. Hybrid strength tests were carried out using an INSTRON 5967 universal testing machine controlled by the Bluehill 3 program and coupled with the ARAMIS measurement system (GOM, Gmbh), enabling the monitoring of deformations in three axes, using a system of high-speed cameras. The results are given of the static tensile test of samples in two printing modes characteristic of the MJF technology – FAST and BALANCE.

Mechanical Properties of Welded Joints of 1.3964 Steel for Computer Aided Engineering (CAE) Purposes

The article presents the study of mechanical properties of welded steel from which the hull of a modern mine destroyer was made. Keeping the tightness of ship compartments during operation depends on the strength of these joints. The results of testing the mechanical properties of 1.3964 steel and its welded joints subjected to a static tensile test were presented, and a Johnson – Cook material model was proposed. The material model can be used in CAE (Computer Aided Engineering) simulations related to hull strength analysis.

Application of the Kolmogorov-Sinai Entropy in Determining the Yield Point, as Exemplified by the EN AW-7020 Alloy

The article presents a method of determining the yield point, applying calculations based on the Kolmogorov-Sinai (K-S) metric entropy model. Data used in metric entropy calculations was obtained during a static tensile test of the AW-7020 aluminium alloy. The methodology of K-S entropy calculations was presented and illustrated by a selected example from a data collection. Analyzing the results obtained, the values of an arbitrary yield point were compared for R02 selected samples with the values ReK−S.