Adhesive Properties of Metals and Metal Alloys

The paper presents the effect of some surface treatment on the bonded joints strength of selected construction materials, adhesive properties of adherends after surface treatment and surface roughness. The aluminium alloys sheets, the titanium sheets and the stainless steel sheets were tested. In the experiments the following surface treatments were investigated: degreasing (chemical cleaning), mechanical treatment, mechanical treatment and degreasing, etching, anodising and chromate treatment. Adhesive joints were formed with a two component epoxy adhesive, Loctite 3430. Adhesive joint tensile-shear strength tests were performed in accordance with EN DIN 1465 standard on Zwick/Roell Z100 and Zwick/Roell Z150 testing machines. Adhesive properties were determined by surface free energy and surface free energy was determined by the Owens-Wendt method. The roughness of specimens was qualified by the method for measuring contact roughness, using an M2 profilometer manufactured by Mahr. The surface view was obtained by used NanoFocus uscan AF2. Results obtained from adhesive joint strength tests of materials evidence that surface treatment plays an important role in increasing strength of analysed joints. Tests indicate that in numerous instances this is mechanical treatment only or mechanical treatment followed by chemical cleaning which translate to the highest joint strength. The surface treatment method which introduces extensive changes in the analysed materials surface geometry is mechanical treatment. The results of surface roughness parameters measurement carried out on test samples subjected to anodising indicate that anodising has an impact on the height of surface irregularities. The application of various surface treatments in different structural materials allows modification of their adhesive properties, determined by the surface free energy. It was noted that different surface treatments contribute not only to the surface free energy changes but to the SFE components share in the total value. In the majority of variants of EN AW-2024PLT3 aluminium alloy sheet surface treatment the dispersive component amounted to the 93-99% of the total surface free energy. The assumption then should be that in order for the determination of a particular surface for adhesive processes to be comprehensive it should account for the adherends surface geometry as well as its adhesion properties. The geometry of surface can influence the mechanical adhesion and the surface free energy is connected with both mechanical adhesion and the other constituent of adhesion – proper adhesion

Cold-Cured Bisphenolic Epoxy Adhesive Filled with Low Amounts of {CaCO}3: Effect of the Filler on the Durability to Aqueous Environments

The effects of aging exposures to three non-saline aqueous environments on the compressive mechanical properties of a calcium carbonate-filled bisphenolic epoxy adhesive, cold-cured with the addition of two curing agents suitable for the cure at ambient temperature (i.e., Mannich base and triethylenetetramine), were assessed. The amount of the added filler (CaCO3) varied from 1 to 3 g per 100 g of resin; the immersion times in each of the selected medium varied from 1 to 10 months. It was found that the mechanical properties measured in compression mode on cylindrical specimens of unfilled and CaCO3 -loaded epoxy were scarcely influenced by the kind of curing agent employed; only the compressive modulus was limitedly affected by this parameter. Referring to the behavior when aged in water, the CaCO3 -filled epoxies displayed noticeable growths in modulus, small reductions in strength, and limited variations in strain, with a certain influence of the exposure time, especially when comparing the properties at the lowest time with those at medium–long times. On the basis of the results of statistical MANOVA analysis, it can be concluded that among the compositional factors (i.e., the type of curing agent employed to cure the epoxy compounds and the micro-filler content), only the amount of CaCO3 filler significantly affects the compressive modulus

Mechanical properties of hand-making polyester composites

The aim of this paper is to determine the effect of arrangement of fibreglass fabric plies in a polymer composite on a strength. Based on the experimental results, the real effect of plies arrangement and their most favourable configuration with respect to strength is determined. The experiments were performed on 4 types of handmade composites which had different fibre orientations and thicknesses. The first three of the composites had three plies of fabric. The plies arrangement in Composite I was unchanged, in Composite II the central ply had the 45 degrees orientation, while in Composite III the outside ply (tangential to the adhesive layer) was oriented at 45 degrees. In contrast. Composite IV consisted of five plies with unchanged arrangement. Composite plates were first cut into smaller specimens and then after stabilizing, the composite specimens were subjected to strength tests. The highest tensile strength and elongation are obtained for Composite IV, which was the higher the thickness from the tested composite samples, but for this composite the tensile modulus was lowest value. Composite II has the lowest values of strength parameters among the tested composites, which contain three plies and central ply has the 45 degrees orientation.Web of Science12212011

A choice of the optimum cutting ranges for cutting nozzles a-sd for selection of metallurgical material.

On the market there are plenty of machines for cutting of steel via a mixture of oxygen and flammable gases. Various manufacturers provide several types of torches, cutting nozzles and other equipment in their product range. Cutting nozzles are a component that significantly affects quality of cutting based in set parameters. However, data from catalogues and manuals by manufacturers on cutting parameters of nozzles are rarely in use in real conditions. That is why optimum cutting conditions for cutting via nozzles A-SD made by RHONA were tested and the final results were compared with those in the catalogue for a proper use in practice.Web of Science12311310

Biological Effects and Toxicity of Compounds Based on Cured Epoxy Resins

The aim of this work was to investigate selected biological and toxicity properties of cured epoxy resin-based compounds based on a bisphenol A epoxy resin, cold-cured by a polyamide and containing two types of metal powders (aluminum and copper). This study involved cytotoxicity analysis, pH measurements, absorbance measurements and sterilization. The cytotoxicity analysis was conducted to determine the harmful degree of the cured epoxy resin. Aimed at identifying toxic agents in cured compounds, the cytotoxicity analysis involved absorbance measurements in an entire wavelength range. Cytotoxicity and absorbance results demonstrated that the extracts of all the tested resin samples had no cytotoxic effects on the cells of living organisms. The absorbance values obtained over the entire wavelength range did not point to the formation of aggregations, which proved that no toxic agents harmful to living organisms were extracted from the resin samples. Based on the results obtained, it can be concluded that all tested compounds, based on epoxy resins, which are also used as adhesives in various applications, are essentially safe materials when using such formulations in a cured state

WŁAŚCIWOŚCI MECHANICZNE WYBRANYCH KLEJÓW EPOKSYDOWYCH

The article presents the results of tests of mechanical properties of selected epoxy adhesives. The study used 6 types of adhesive compositions prepared from three types of epoxy resins Epidian 5, Epidian 53 and Epidian 57, which were mixed with the hardener PAC 100: 100 and 100: 80. During the implementation of research two sets of samples were prepared: samples of adhesives in hardened state and single lap adhesive joints of steel sheet C45 made by using these epoxy adhesives. By studying the results of strength tests of adhesive joints and adhesive layer thickness, was observed a dependence – when the weld has a smaller thickness, the strength of the connection is greater. One single-lap adhesive joints prepared with Epidian 57 / PAC / 100: 80 have the highest strength (14.9 MPa), with the smallest adhesive thickness (0.2 mm). When using Epidian 5 / PAC / 100: 80, the lowest static strength (6.69 MPa) was obtained.W artykule zaprezentowano wyniki badań właściwości mechanicznych wybranych klejów epoksydowych. W trakcie badań wykorzystano 6 kompozycji klejowych przygotowanych z 3 rodzajów żywic epoksydowych: Epidian 5, Epidian 53 oraz Epidian 57, które mieszano z utwardzaczem PAC w stosunku 100:100 oraz 100:80. Podczas realizacji badań przygotowano 2 zestawy próbek: próbki klejów w stanie utwardzonym oraz próbki jednozakładkowych połączeń klejowych blachy C45 wykonanych za pomocą wymienionych klejów. Analizując wyniki badań wytrzymałości połączeń klejowych i grubości warstwy kleju zauważono pewną zależność – im spoina ma mniejszą grubość, tym wytrzymałość połączenia jest większa. Jednozakładkowe połączenia klejowe przygotowane za pomocą kleju Epidian 57/PAC/100:80 uzyskały największą wytrzymałość (14,9 MPa), przy najmniejszej wartości grubości spoiny klejowej (0,2 mm). W przypadku zastosowania kleju Epidian 5/PAC/100:80 uzyskano najmniejszą wytrzymałość statyczną (6,69 MPa)

Impact of cutting tool geometry on the dynamic load of system in the machining process of nickel Alloy 625

The article is focussed on comparing and determining the impact of the cutting geometry of the cutting tool due to dynamic load on system and microgeometry machined surface. For longitudinal turning nickel alloy Alloy 625 (W. Nr. 2.4856) rounded indexable cutting insert was used (RCMT 10T3M0 - F2) and its equivalent squared indexable cutting insert (SNMG 120412 - MR3) coated with fine-grained PVD (Ti, Al) N + TiN. Experimental testing of nickel Alloy 625 was under predetermined cutting conditions. In the selected depth of the removed material of 0.5 mm and 1.5 mm was measured in the course of machining the size of the individual components of cutting forces.Web of Science1032312

Influence of the assembly method of sleeve joints on their strength

The aim of the study was to compare the strength of assembly joints of sleeve elements made of different structural, polymeric materials. Experimental tests were carried out to determine the mechanical properties of adhesive and welded joints. Adhesive joints were made of polyvinyl chloride pipes with the use of three types of adhesives: Epidian 53/PAC/100:80, Epidian 53/TFF/100:22, Vodaro 15010-VO. The welded joints were made of polypropylene pipes. All of the joints have been made with the use of a pipe fitting allowing for correct joints. Then the completed joints were subjected to destructive strength tests. The obtained results made it possible to carry out statistical analysis, which aimed at determining significant differences between the various methods of assembly. The tests carried out proved that the adhesive joints made with the Vodaro 15010-VO one-component adhesive were characterized by the highest strength - 2.30 MPa. The lowest strength was obtained in the case of adhesive joints made with Epidian 53/TFF/100:22 - 0.45 MPa epoxy ad-hesive composition. Statistical analysis showed that the strength obtained in case of adhesive joints made with epoxy compositions differs significantly from the strength of adhesive joints made with Vodaro adhe-sive. No significant differences at the assumed level of significance α=0.05 were also observed in the case of the strength of PP-R adhesive joints made with Vodaro adhesive and the strength of PVC-U welded joints