Mariusz Kłonica

Comparative Analysis of Energetic Properties of Ti6Al4V Titanium and EN-AW-2017A(PA6) Aluminum Alloy Surface Layers for an Adhesive Bonding Application

The purpose of this article is to present energetic properties of surface Ti6Al4V titanium as well as surface EN-AW-2017A(PA6) aluminum alloy layers. Values of surface free energy after selected mechanical operations and ozonation were compared. In addition, the influence of different values of ozone concentration on surface layer energetic activation was analyzed. Dispersive and polar components of surface free energy were of particular concern. Comparative evaluation of shearing strength of Ti6Al4V titanium and EN-AW-2017A(PA6) aluminum alloy single-lap adhesive bonded joints were presented. Results can be used as pro-ecological methods of titanium and aluminum alloys preparing for applications where adhesive phenomenon is important.

Effect of a Notch on Impact Resistance of the Epidian 57/Z1 Epoxy Material after "Thermal Shock"

Adhesive bonding is increasingly being applied as structural joining technique in highly reliable machines and appliances operating in the circumstances of variable thermomechanical loads.The manufactured specimens of the Epidian 57/Z-1 epoxy material had been subjected to cyclic thermal loading, with respect to a defined program, in a thermal shock chamber within a temperature range of ‑40°C to +60°C for 200 cycles. The accepted temperature range was typical for machinery maintenance, including the aircraft.The aim of the research was first of all determination of thermal load (fatigue), as well as the presence of notch effect on the resistance to fracture.A significant measure of the adhesive bonds quality is the repeatability of the strength examination results, both in the summary and long lasting tests. It is often more important criterion for the adhesive joint selection than higher strength of the joints using the particular adhesive.The obtained results of the conducted research have been elaborated statistically with respect to the appropriate scientific standards.

Comparative Analysis of Shear Strength of Single-Lap Adhesive Joints after "Thermal Shock"

The paper presents a comparative analysis of static shear strength of single-lap adhesive joints of 316L steel, before and after mechanical treatment with a coated abrasive tool. The research was of comparative nature and focused on adhesive joints subjected to variable thermal stress and adhesive joints not subjected to such shock. Adhesives based on epoxy resins were used. The results of static shear strength tests of single-lap adhesive joints for different variations of material preparing were analysed. The obtained results were analysed statistically and in compliance with relevant scientific standards. The scope of tests covered a relatively short fatigue cycle, i.e. 200 cycles in the range of temperatures between-40°C and +60°C. The main aim of the research was to determine the relation between joint strength and thermal fatigue. The paper presents conclusions resulting from the conducted research.

Effect of the AWJM Method on the Machined Surface Layer of AZ91D Magnesium Alloy and Simulation of Roughness Parameters Using Neural Networks

This paper investigates the effect of change of the abrasive flow rate and the jet feed on the effectiveness of machining of AZ91D casting magnesium alloy. The evaluation of the state of the workpiece surface was based on surface and area roughness parameters (2D and 3D), which provided data on: irregularities formed on the workpiece edge surface (water jet exit), the surface quality after cutting, the workpiece surface chamfering, microhardness of the machined surface, and of specimen cross-sections (along the water jet impact). The process was tested for two parameter settings: abrasive flow rate 50 at cutting speed vf = 5–140 mm/min, and abrasive flow rate 100% (0.5 kg/min) at vf = 5–180 mm/min. The results demonstrate a significant effect of the abrasive flow rate and the jet feed velocity on the quality of machined surface (surface roughness and irregularities). In addition, selected 2D surface roughness parameters were modelled using artificial neural networks (radial basis function and multi-layered perceptron). It has been shown that neural networks are a suitable tool for prediction of surface roughness parameters in abrasive water jet machining (AWJM).

DETERMINING THE VALUE OF SURFACE FREE ENERGY ON THE BASIS OF THE CONTACT ANGLE

This paper presents the results of tests concerning the value of surface free energy on the basis of measurements of contact angle with measure liquids: distilled water and diiodomethane. The surface of steel-316L samples was modified in an ozone atmosphere, and the concentration of ozone and the conditioning time of the samples in the reaction chamber were changed. The results of tests concerning the measurements of the value of surface free energy were subject to analysis. Also analysed were the components of SFE: the polar and dispersive components. The obtained test results were analysed in statistical terms. The paper ends with conclusions.

Comparative analysis of effect of thermal shock on adhesive joint strength

The aim of this study was a comparative analysis of static shear strength of single-lap adhesive joints of 316L steel adherends, measured prior to and after mechanical treatment with a P320 grit coated abrasive tool. The study was of comparative nature and focused on adhesive joints subjected to thermal cycling. The tests were carried out on joints bonded with Epidian 5 and Epidian 6 epoxy adhesives hardened with Z1 and PAC curing agents. The static shear strength tests results of single-lap adhesive joints were analysed with regard to different surface treatment variants. The scope of tests covered a relatively short fatigue cycle, i.e. 200 cycles in the range of temperatures between -40oC and +60oC. This paper includes the surface free energy and selected surface roughness parameters of substrates and images showing the surface of adherends before and after mechanical treatment with P320 grit coated abrasive tool.

IMPACT OF THERMAL FATIGUE ON YOUNG’S MODULUS OF EPOXY ADHESIVES

The following paper presents a comparative analysis of two epoxy-based adhesives: Hysol 9466 and Hysol 3421, prior to and after thermal shock testing. The tests focused on determining Young’s modulus. Epoxy-based materials are among the most widespread adhesive materials used as universal structural adhesives. The prepared epoxy samples (Hysol 9466 and Hysol 3421) were subjected to thermal shock cycling tests, according to a specified programme, in a thermal shock testing chamber, at a temperature range –40 °C to +60 °C and in the number of 200 cycles. Conclusions from the tests are presented at the final stage of the paper.