International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

The paper presents the results of a research focused on the application of laser surfacing of functional surfaces using an additve material in the form of a wire. Cladding is made in a single layer using a robot. The quality of the cladding layer was evaluated by ultrasonic inspection. Possible occurrence of internal defects was assessed. Macrostructures and microstructures were analyzed on metallographic sections using light microscopy. Influence of the used additive material and the cladding parameters on the microhardness behaviour in the individual parts of the test specimens was also evaluated.

The paper presents experimental work focused on the wear resistance of clads made with OPEN ARC technology (MOG) and clads with cycled cladding nozzle. The distribution of carbide phases by electron beam was evaluated. The influence of the tempering temperature of the clads on the hardness of the layers was determined. Tests of the resistance of the clads to abrasive wear were carried out.

CMT technology provides significant advantages, such as reduced deformation due to high temperatures, high welding speed and a significant reduction in spatter compared to the MIG/MAG method. The experimental work was focused on verifying the possibility of renovating the surfaces of molds for high-pressure aluminum casting using CMT technology. A mold wear analysis was performed and a method of restoring functional surfaces was proposed. Two types of additive materials were used – Thermanit 625 and Thermanit X. The quality of the layers was evaluated by SEM, EDX microanalysis and the coefficients of friction of the layers were determined by the Ball-ondisc method. The renovation layers were also subjected to an immersion test in Al alloy at 680 °C.

The paper presents the results of research focused on the renovation of worn surfaces. Four progressive welding technologies were used – Cold Metal Transfer, MIG Pulse, TOP-TIG and laser technology. The layers were evaluated by non-destructive tests – visual, capillary and ultrasonic methods. The layers were evaluated under dry-friction adhesive wear conditions by the Ball-On-Disc method. A Si3N4 bead was used. Analyzes confirmed the impact of the renovation method on the quality of the resulting surface.

Molds designed for high-pressure casting of aluminum are exposed to very intense thermal, mechanical but also chemical stress during their operation. This stress leads to a synergistic effect of a combination of high-temperature corrosion processes in molten metals, under real conditions associated with mechanical wear. High-temperature corrosion in the environment of liquid metals occurs in the foundry industry, when casting molten metal most often into steel molds. Repair of worn parts of molds by welding, which can be performed even after their irreversible surface degradation, is a very efficient, cost-effective and envi-ronmentally acceptable form of their maintenance, while the chemical and physical properties are welded layers if they exceed the properties of the original material.

The paper presents the results of the research of the evaluation of the overlay layers quality made by the fusible arc methods. By applying arc welding methods, it is possible to significantly extend the life of injection molds and thus significantly reduce production costs. The newly formed layers must meet a number of requirements so as not to degrade the advantages of high-pressure injection technology over conventional casting technologies. High pressure casting solves most of the problems of conventional casting technologies such as: porosity of the casting, high surface roughness, long casting time, inability to produce thin cross-sections and low dimensional accuracy. During exploitation, the mold surface is damaged, mostly by thermal cracking and combined adhesive-abrasive wear. Material used for high pressure die casting permanent mold is a medium alloyed hot tool steel Uddeholm Dievar. Layers were made using three types of filler materials on the Fronius TransTig 4000. To eliminate the effect of mixing, three layers were made. The quality of the deposits was assessed by non-destructive and destructive tests.

The paper presents results of quality evaluation of hardfacing layers applied to functional parts of dredger teeth. Layers were made by arc welding methods MMAW and FCAW. High-alloy types of filler materials were used in the experiment. Their chemical composition allows the production of overlay layers with a high content of carbide particles. These particles ensure high resistance to abrasive wear of the layers. Excavator teeth were made by casting high-grade manganese steels Grade B-3 A 128 / A128M-93. In the experiments, the presence of surface defects of the weld deposit was assessed by visual inspection. The resistance of the hard-facing layers to the effects of abrasive wear was assessed using a Di-1 experimental apparatus and evaluated on the basis of weight loss.