MODIFICATION OF POWDER MATERIAL BY COMPACTION PROCESSING

There are different criteria for assessing the appropriateness of an agglomeration technology in the deployment processing of dry, fine and dirty dust burdening in the communal and working environment. Besides the benefit of the environment components, the agglomeration technology offers the possibility of re-processing the material as the primary raw material within a wide range of industries. Preliminary tests have shown that the compressed material remains in the memory from the previous compression. For returning the already processed material into a primary production, it is essential that it is reformed without the need for additional materials, a requirement that can be problematic. This article deals with the modification of a powder material (powder dust from the manufacture of friction components) and the investigation of its properties before and after the compaction processing

DESIGN OF PARTICULATE MATERIAL COMPACTOR ROLLS DIAMETER

At present, in a period of an industrial expansion great emphasis is placed on the environment. That means aiming for a reduced energy consumption, and also lessening dustiness from very fine powder material. This category also includes particulate material agglomeration processes. Because this process is very energy-intensive, it is necessary to correctly design these devices. The aim of this paper is to focus on a theoretical design of a production compactor with the rolls diameter for an experimental particulate material, based on Johanson’s theory and experimentally measured material properties. The material used for experimental measurements was an NPK-based industrial fertilizer consisting of several components. The results of this paper is the dependence of the ratio of the maximum compression pressure to the initial compression pressure from the rolls diameter of the proposed compactor

Analysis of Pharmaceutical Excipient MCC Avicel PH102 Using Compaction Equations

This paper focuses on the characterization of the tabletting process and analysis one of the most common pharmaceutical excipients MCC Avicel PH102 by Heckel, Kawakita, Cooper-Eaton and Adams compaction equations. Experimental material was determined by measuring its parameters as particle size distribution, angle of wall friction and flow properties and for more detailed characteristics of the material particles, microscopy images of the powder before and after compressing were created

Hot Deformation Process Analysis and Modelling of X153CrMoV12 Steel

Analysis of the high temperature plastic behavior of high-strength steel X153CrMoV12 was developed in the temperature range of 800–1200 °C and the deformation rate in the range of 0.001–10 s−1 to the maximum value of the true strain 0.9%. Microstructural changes were observed using light optical microscopy (LOM) as well as atomic force microscopy (AFM). The effect of hot deformation temperature on true stress, peak stress and true strain was evaluated from the respective flow curves. Based on these results, steel transformation was discussed from the dynamic recovery and recrystallization point of view. Furthermore, a present model, taking into account the Zener–Hollomon parameter, was developed to predict the true stress and strain over a wide range of temperatures and strain rates. Using constitutive equations, material parameters and activation energy were derived, which can be subsequently applied to other models related to hot deformation behavior of selected tool steels. The experimental data were compassed to the ones obtained by the predictive model with the correlation coefficient R = 0.98267. These results demonstrate an appropriate applicability of the model for experimental materials in hot deformation applications

Polyorganosilazane/GPTMS functionalized silica coatings as an integrated corrosion–resistance system for AA2024-T3 aluminum alloy

A hybrid coating based on polyorganosilazane (Durazane® 1800) combined with 3-glycidyloxypropyltrimethoxysilane (GPTMS) was successfully synthesized to improve the corrosion resistance of the AA2024-T3 aluminum alloy. The polymers were cross–linked with the addition of tetra-n-butylammonium fluoride (TBAF), and the hybrid coatings were deposited on aluminum substrates by dip coating and dried at 120 °C. Crack-free films with a thickness of 13 μm were obtained. Field emission electron microscopy (FESEM) analysis indicated that the synthesized hybrid films were smooth, homogenous, and devoid of cracks. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) studies demonstrated that the intensity of the Si–N–Si peak was maintained, showing that the backbone of the polysilazane was preserved after the addition of GPTMS. Nuclear magnetic resonance (NMR) spectroscopy indicated that glycidoxypropyl groups were still present in the Si–O–N network of the modified polysilazane. Contact angle measurements indicated that the hybrid coatings were hydrophobic, with a measured contact angle of 93 ± 6°. The electrochemical results confirmed that the synthesized hybrid coatings improved the corrosion resistance of the aluminum substrate in 3.5 wt% NaCl solution. This suggest that the modified polyorganosilazane coating is an effective solution for developing anti-corrosive coatings on metal substrates, offering excellent adhesion strength and good scratch resistance

Modifying the properties of finely ground limestone by tumbling granulation

Calcium carbonate in the form of finely ground limestone is a material that has found its application in a wide range of industries, in the chemical, rubber, agricultural, and paper industries, is used for desulfurization of boilers and other. In civil engineering, ground limestone is used for the production of building materials, plaster and mortar mixtures, as a filler in concrete mixtures, in road construction, and as an essential component of mastic asphalt. This paper deals with examining the modification of the properties of finely ground limestone by the tumbling agglomeration method. It has been shown that the components of concrete with a round grain have a positive effect on the pumping of concrete in comparison with an elongated grain or the rough surface of crushed stone. The experiments will be carried out on a granulation plate using a variety of granulation liquid. The agglomerates and their properties were compared with untreated finely ground limestone, with a focus on detecting changes in compressibility, density and particle size. The output of this paper is a description and graphical representation of the changes in the properties of ground limestone before and after the agglomeration process

The Influence of Q & T Heat Treatment on the Change of Tribological Properties of Powder Tool Steels ASP2017, ASP2055 and Their Comparison with Steel X153CrMoV12

In connection with the growing importance of the efficiency and reliability of tools in industrial sectors, our research represents a key step in the effort to optimize production processes and increase their service life in real conditions. The study deals with the comparison of the tribological properties of three tool steels, two of which were produced by the powder metallurgy method—ASP2017 and ASP2055—and the last tool steel underwent the conventional production method—X153CrMoV12. The samples were mechanically machined with the finishing technology of turning and, finally, heat treated (Q + T). The study focused on the evaluation of hardness, resulting microstructure, wear resistance, and coefficient of friction (COF). The ball-on-disc method was chosen as part of the COF and wear resistance test. The tribological test took place at room temperature with dry friction to accelerate surface wear. The pressing material was a hardened steel ball G40 (DIN 100Cr6). Measurements were performed at loads of 10 N, 6 N, and 2 N and turning radii of 13 mm, 18 mm, and 23 mm, which represents a peripheral speed of 0.34, 0.47, and 0.60 m/s. The duration of the measurement for each sample was 20 min. The results showed that the COF of powder steels showed almost the same values, while a significant difference occurred with the increase of the radius rotation in the case of conventional steel. The results within the friction mechanism showed two types of wear, namely, adhesive and abrasive wear, depending on the Q + T process. From a tribological point of view in terms of wear, it was possible to state that the material ASP2055 after Q + T showed the lowest rate of wear of all the tested steels