Browse

You are looking at 51 - 60 of 2,051 items for :

  • Substances and Products x
Clear All
Open access

J. Michalczyk

Abstract

The article presents a newly developed method for single-operation extrusion of conical radiators. This is the author’s radiator manufacturing method being the subject of a patent application. The proposed method enables the manufacture of radiators either with or without an inner opening and with an integral plate. Selected results of numerical computations made within Forge®3D, a finite element method (FEM)-based software program, were presented during the analysis of the process. A comparative analysis of the proposed manufacturing method using the double-sided extrusion method was also made.

The proposed manufacturing method is assumed to produce radiators in a single technological operation with the stock material being standardized 30 mm-diameter aluminium bars. The objective of the developed method is also to reduce the energy-force parameters.

Open access

D. Ozimina, M. Madej and J. Kowalczyk

Abstract

The aim of the study was to determine the effectiveness of the biodegradable cutting fluid used instead of classical, usually toxic. This paper presents the results of tribological studies of a-C:H coatings formed on HS6-5-2C steel by plasma-assisted chemical vapour deposition. The coating structures were examined using a JSM-7100F SEM. The coating microhardness was measured with a Matsuzawa tester. The surface texture analysis was performed before and after the tribological tests with a Talysurf CCI Lite optical profiler. The tribological properties were investigated using a T-01 M tester and a T-17 tester. The tests were carried out under dry friction conditions and lubricated friction conditions using a lubricant with zinc aspartate. The test results show that the layer formed at the interface prevented the moving surfaces. The investigations discussed in this paper have contributed to the development of non-toxic and environmentally-friendly manufacturing because of the use of biodegradable cutting fluid and thin, hard coatings.

Open access

T. Pała and I. Dzioba

Abstract

The paper presents the results of two butt welded joints by conventional method. The welding process was performed using a variety of linear welding energy. The studies included experimental and computational part. In experimental studies determined the distribution of hardness and mechanical properties of the individual analyzed sections of welded joints. The data obtained were intended to determine the extent of zones in the welded joints that have certain strength characteristics. Also conducted uniaxial tensile tests of welded joints with the registration of displacement fields on the surface of specimens by means of Aramis video-system what the final result are images of strain fields map on the surface of welded joints. The resulting strain values were compared with the results of numerical computations FEM.

Open access

D. Nowak, B. Gal, K. Granat, G. Jaworski and R. Więcławek

Abstract

The presented research was aimed at searching for an exact and effective method of determining moisture content in traditional moulding sands. By measuring resonance frequency and quality factor of a waveguide resonance cavity, relative permittivity was determined for different synthetic moulding sands. Analysis of the presented results confirms a linear relation between relative permittivity values and moisture content values in the selected traditional moulding sands. The obtained linear relationship can be used as a reference characteristic for evaluation of humidity of moulding sand.

Open access

A.W. Bydałek, P. Migas, W. Wołczyński and J. Karwan-Baczewska

Abstract

This paper discusses the impact of complex chemical reagents during the process of decopperisation of slag. The beneficial effect of carbide response factors with the participation of nitrogen was indicated as well as the role of stimulators surfactants. Based on the results of the research the basic structure of the slag during decopperisation was systematized. The effects of coagulation of droplets of copper in the slag were shown in this paper.

Open access

M. Kciuk and S. Lasok

Abstract

The paper presents the influence of heat treatment on the structure and corrosion resistance of X5CrNi18-10 steel. To determine the structure which has been obtained after heat treatment the methods of light and scanning electron microscopy with EDS microanalysis were used. The electrochemical corrosion properties of the investigated steel were studied in 3.5% NaCl solution using potentiodynamic polarization tests. Basing on the registered curves, the corrosion current, polarization resistance and corrosion potential were determined. The corrosion tests were followed by fractographic researches.

Open access

N. Gidikova, M. Sulowski, V. Petkov, R. Valov and G. Cempura

Abstract

Chrome plating is used to improve the properties of metal surfaces like hardness, corrosion resistance and wear resistance in machine building. To further improve these properties, an electrodeposited chromium coating on steel, modified with nanodiamond particles is proposed. The nanodiamond particles (average size 4 nm measured by TEM) are produced by detonation synthesis (NDDS). The composite coating (Cr+NDDS) has an increased thickness, about two times greater microhardness and finer micro-structure compared to that of unmodified chromium coating obtained under the same galvanization conditions. In the microstructure of specimen obtained from chrome electrolyte with concentration of NDDS 25 g/l or more, “minisections” with chromium shell were found. They were identified by metallographic microscope and X-ray analyser on etched section of chromium plated sample. The object of further research is the dependence of the presence of NDDS in the composite coating from the nanodiamond particles concentration in the chroming electrolyte.

Open access

Z. Brytan

Abstract

The paper presents the results of the basic mechanical properties determined in the static tensile test, impact un-notched Charpy test and hardness of austenitic stainless steel type 316L produced by two techniques: classical pressing and sintering in a vacuum with rapid cooling and selective laser melting (SLM). In this work fracture surface of Charpy test, samples were studied.

The results indicate that application of selective laser melting (SLM) makes it possible to double increase the strength properties of components manufactured from austenitic stainless steel type 316L compared to sintering in a vacuum. Resulted in mechanical properties strongly depend on porosity characteristic and the presence of superficial oxides in the case of sintered steel and the character of observed microstructural defects deriving from non-fully melted powder particles and the formation of voids between subsequently melted pool tracks during the SLM.

Open access

M. Dudek

Abstract

The paper presents the analysis of formation of interfacial layer during deposition of diamond like carbon film (DLC) on the 316L stainless steel by capacitive plasma discharge in the CH4 atmosphere. The structure of the interfacial layer of DLC film was strongly affected by the temperature increase during the initial stages of the process. Initially, thin interfacial layer of 5 nm has been formed. As the temperature had reached 210°C, the second phase of the process was marked by the onset of carbon atoms diffusion into the steel and by the interface thickness increase. Finally, the growth of chromium carbide interface, the upward diffusion of chromium and nickel atoms to film, the etching and the decrease of the DLC film thickness were observed at 233°C. These investigations were carried out ex-situ by spectroscopic ellipsometry, X-ray diffraction, X-ray photoelectron spectroscopy and Raman spectroscopy.

Open access

B. Mrzygłód, A. Kowalski, I. Olejarczyk-Wożenska, T. Giętka and M. Głowacki

Abstract

The results of examinations of microstructure and an analysis of its impact on selected mechanical properties of austempered ductile iron (ADI) were presented in the paper. The ADI was produced from the ductile iron containing 1.56% Ni only alloying addition. The effect of the austempering time and temperature on the microstructure and mechanical properties of the examined cast iron was considered. Constant conditions of austenitizing were assumed and six variants of the austempering treatment were adopted. The studyof mechanical properties included a static tensile test, Charpy impact strength test and Brinellhardness measurement.

This work complements the knowledge about alloying additions effect on microstructure and mechanical properties of ADI and focuses on the impact of a single alloying element (Ni).