|Tomasz Reguła, Aleksander Fajkiel, Piotr Dudek, Krzysztof Saja|
The paper presents results of wrought alloys casting trials under external pressure. Three alloys were used in the experiment - namely: 2024, 6061 and 7075. The examinations were conducted on squeeze cast parts that solidified under high pressure (150 MPa) in a Vertical Squeeze Casting machine UBE VSC 500. Gravity castings were used as a reference. The castings were heat treated to T6 condition. DSC and quantitative metallographic examinations were carried out. Mechanical properties were also tested. The advantageous effect of the external pressure has been assessed based on the results of the quantitative metallography and mechanical properties in cast and in the T6 condition.
Keywords: aluminum alloys, wrought alloys, squeeze casting, mechanical properties,
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The aim of this paper was to assess the possibilities and benefits of using low-volume (thinned) samplers for thermal analysis of cast iron. As part of the research, a series of melts of plain cast iron and low-alloy cast iron with different structures were made. After carrying out treatment procedures with the use of magnesium and magnesium-cerium master alloys, the analysis of solidification in standard-sized and low-volume samplers over the adaptive thermal analysis system was made. The structure and strength properties on Y type I and II cast samples were determined. The research has shown benefits from the use of low-volume samplers to test the cast iron crystallization process, especially in the context of thin-walled castings.
Keywords: cast iron, thermal analysis, structure, strength,
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Andrzej Pytel, Andrzej Gazda
The work herein presents the tests to produce austempered vermicular cast iron (AVCI - Austempered Vermicular Cast Iron) and the results of examination of the produced AVCI. The work includes the methodology of heats, the structure of the AVCI before and after austempering, mechanical properties and dilatometer testing.
Keywords: vermicular cast iron, austempered vermicular cast iron, AVCI, structure, strength testing, dilatometer testing,
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Katarzyna Szczepaniak-Lalewicz, Jerzy Tybulczuk
Tests were conducted to develop a new generation of functional nano-coatings used in the foundry industry. The research focused on the introduction of modern and innovative coatings based on nanoparticles of cast elements and active chemical compounds, which during metal solidification will allow the diffusion of these elements into the surface of the solidifying alloy (casting) with the resulting change in the structure of the casting surface owing to the formation of carbides, conferring a significant increase of abrasion wear resistance thereby gaining casting surface.
Keywords: ceramic slurry, iron alloys, nano-coatings, colloidal suspension of metal oxides (binders), modification, diffusion,
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Marek Wawrylak, Wojciech Leśniewski, Katarzyna Szczepaniak-Lalewicz
This paper presents the method of investigating the sol-gel transition by constant speed removal of plates, made of suitable substrate, from an aqueous colloidal binder. The thickness of the deposited colloidal binder layer depends on the particle sizes in the binder. The processing feasibility of colloidal binders reduced by aggregation of particles is difficult to evaluate without access to special measuring equipment. Development of a simple method for prompt evaluation of performance parameters in colloidal binders may have industrial applications.
Keywords: sol-gel transition, colloidal binders, casting ceramic moulds, gravimetric measurement, dip coating,
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Artur Kudyba, Natalia Sobczak, Aleksandra Siewiorek, Patrycja Turalska, Adam Klasik, Jerzy Bieliński, Anna Sałacińska, Rafał Kozera
The aim of this study was to determine the effect of the chemical composition of Ni-P coating on the wettability kinetics of SAC305 liquid solder in contact with the Ni-P coating. The study was conducted in vacuum, at 230°C, for 5 minutes, using the sessile drop method in combination with a separate heating of the two test materials, allowing for experimental determination of the contact angle θ. The study used a SAC305 solder (Sn base, Ag 3 wt. %, Cu 0.5 wt. %) and a nickel substrate (Ni 99.8 wt. %) onto which Ni-xP coating of two different levels of phosphorous was applied (x = 4.3 wt. %, or 11.6 wt. %). After the tests of wettability were performed, structural analysis of the surface of the samples was performed by scanning electron microscopy, focusing on the observation of the border SAC305/substrate. In order to determine the effect of phosphorus in the Ni-P coating on the strength of the SAC305/Ni-xP/Ni joints formed, cross sections of samples were tested for shear strength using the improved method of the push-off shear test. It was found that, for the selected range of 4.3 ≤ P ≤ 11.6, increase in the phosphorus content in the coating improves the wettability of the liquid systems tested with the SAC305 solder, but it is an apparent effect resulting from the solder’s penetration of the structural discontinuities formed in the layer of Ni-11.6P, due to phase transitions. For the SAC305/Ni-11.6P/Ni sample, value of the contact angle θ = 5 4° i s mechasmaller, as compared to the SAC305/Ni-4.3P/Ni sample, for which θ = 75°, the shear strength of the joints produced shows virtually no changes, for the SAC305/Ni-11.6P/Ni sample τmax = 15.6 MPa, as compared to τmax = 14.2 MPa for the SAC305/Ni-4.3P/Ni sample.
Keywords: SAC305, Ni-P coating, contact angle, wetting angle, wettability kinetics, lead-free soldering,
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Adam Tchórz, Andrzej Gil
The launch of new methods in the technical metrology area is a material factor determining the quality of the products. The paper presents the methodology of analysis of metrological tests conducted with the use of computed tomography and an optical 3D scanner. These devices allowed us to obtain virtual objects and conduct 3D spatial analyses. The paper presents the operating principle of these devices and analyses their capabilities based on selected castings. The results of the tests are presented with the support of determined dimensions and colour maps on the model surface. The accuracy of measurements in individual methods was assessed.
Keywords: metrology 3D, 3D scanning, X-ray computed tomography (X-ray CT), optical 3D scanner,
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Jarosław Piekło, Stanisław Pysz, Marcin Małysza
Cellular structures are critical components which perform as energy absorbers in the defense, aerospace and automotive industries. Simultaneous application of topological optimisation algorithms for strength forming, solidification simulation software, additive manufacturing (AM) methods and solidification process control technologies may have a significant impact on building lightweight and strong structures. The shape of such structures is optimally adapted for transmission of loads with certain action of external forces and bearing methods. The purpose of this paper is to present the potential released by joint application of topological optimisation methods and AM methods in building of casting equipment for production of cellular castings which can resist compressive forces.
Keywords: topological optimisation, cellular castings, additive manufacturing processes,
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Jerzy Żebrowski, Beata Czawa, Anna Pawlińska
This article presents the evaluation method for nitrated and carbonitrided layer on the surface of the examined material (steel). The above mentioned method comprises the measurement of layer thickness, as well as decomposition of elements occurring in it, with the use of QDP program (quantitative profile analysis) with which GDS 850A glow discharge optical emission spectrometer is equipped. Conditions presented in this article enable us to assess the developed method as useful in the examination of nitrated and carbonitrided layers.
Keywords: glow discharge optical atomic emission spectrometry, nitrated steel, layer profile analysis,
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