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1

Influence of HIP sintering technique on the reliability of the mechanical properties of brass-an experimental study

Alnomani Salah N.

Diagnostyka

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2022

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Vol. 23, No. 3

art. no 2022311

EN

The reliability of the mechanical properties of any product plays an important role in the longevity of the product to work properly under various working conditions. In the present study, the effect of preparing brass alloy on its mechanical properties was experimentally studied. Samples of brass (60% Cu-40% Zn) were prepared by hot iso-stating pressing (HIP) sintering method and some main mechanical tests were performed on them included porosity, density, hardness and compression tests. Results of these tests were compared with corresponding tests on commercial brass alloys produced by casting in order to show the effect of the method of preparing on their mechanical properties. There was a significant improvement in the hardness and strength of the sintered alloy due to the increasing in density and decreasing in porosity comparing with the corresponding other casting's alloys. Results showed an improvement in the density values by 8.4% as a result of the significant reduction in the porosity values from 8.65% to about 0.43%. As a result, the strength of the alloys prepared by the heat pressing method has jumped to a value of 600MPa compared to the traditional castings that have a strength of 343MPa.

2

Hot isostatic pressing influence on the mechanical properties of selectively laser-melted 316L steel

Kluczyński J., Śnieżek L., Grzelak K., Oziębło A., Perkowski K., Torzewski J., Szachogłuchowicz I., Gocman K., Wachowski M., Kania B.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2020

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Vol. 68, nr 6

1413--1424

EN

Industries that rely on additive manufacturing of metallic parts, especially biomedical companies, require material science-based knowledge of how process parameters and methods affect the properties of manufactured elements, but such phenomena are incompletely understood. In this study, we investigated the influence of selective laser melting (SLM) process parameters and additional heat treatment on mechanical properties. The research included structural analysis of residual stress, microstructure, and scleronomic hardness in low-depth measurements. Tensile tests with specimen deformation analysis using digital image correlation (DIC) were performed as well. Experiment results showed it was possible to observe the porosity growth mechanism and its influence on the material strength. Specimens manufactured with 20% lower energy density had almost half the elongation, which was directly connected with the porosity growth during energy density reduction. Hot isostatic pressing (HIP) treatment allowed for a significant reduction of porosity and helped achieve properties similar to specimens manufactured using different levels of energy density.

3

Magnetooptyczne właściwości polikrystalicznego tlenku itru

Kruk A.

Materiały Ceramiczne

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2018

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T. 70, nr 3

221--232

PL

Właściwości magnetooptyczne ceramiki przeźroczystej zostały przedstawione w prezentowanym artykule. Do otrzymania polikrystalicznego tlenku itru została wykorzystana metoda izostatycznego prasowania na gorąco (HIP, ang. hot isostating pressing), dzięki której otrzymano zwarty spiek o przeźroczystości powyżej 50% w zakresie światła widzialnego. Badanie mikromorfologii powierzchni próbki ujawniła dobrze rozwinięte regularne ziarna o wielkości kilku mikrometrów. Nie stwierdzono występowania porów w ziarnach. Badania strukturalne metodą XRD proszku i spieku potwierdziły obecność w nich tylko fazy regularnej Y2O3. Do wyznaczenia stałej Verdeta w omawianym materiale zbudowano zaawansowany układ pomiarowy. Pomiar efektu Faradaya w badanym materiale Y2O3 wykazał wartości od -180 deg/(T∙cm) do 3 deg/(T∙cm) w zakresie 400-1000 nm. Otrzymany tlenek itru nadaje się do wykorzystania jako materiał magnetooptyczny, a jego dalsze modyfikacje powinny przynieść poprawę tego efektu.

EN

Magneto-optical properties of Y2O3 transparent ceramics are presented in this article. A method of hot isostatic pressing (HIP) method was used to prepare of polycrystalline yttrium oxide, thanks to which dense sinter with a transparency of more than 50% in the visible spectrum was obtained. Examination of micromorphology of the sample surface revealed well-developed regular grains of several micrometers in size. No pores in the grains were found. XRD measurements confirmed only a cubic phase in powder and sinter. An advanced measurement system was built to determine the Verdet constant in the discussed material. Measurement of the Faraday effect in the tested Y2O3 showed values from -180 deg/(T∙cm) to 3 deg/(T∙cm) in the 400-1000 nm. The obtained yttrium oxide is suitable for use as a magneto-optical material, and its further modifications should improve this effect.

4

Processing and properties of sinters prepared from 316L steel nanopowders

Krztoń H., Kolesnikow D., Paduch J., Molenda R.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 21, nr 2

73-76

EN

Purpose: The results of the research work on processing the sinters obtained from nanocrystalline powders of 316L steel are presented. Design/methodology/approach: The 316L steel powder has been mechanically alloyed from a set of elementary powders with use of Fritsch Vario-Planetary Mill Pulverisette 4. The time of 12 hours of milling has been needed for producing the powder. The X-ray diffraction has been used for controlling of the mechanical alloying process. The Rietveld method has been used to calculate the contents of the components of the powder. Cold and hot isostatic pressing have been applied to make the compacts. The pressure of 500 MPa and 900 MPa of cold pressing, and 150 MPa of hot pressing have been used. The green compacts have been pressed isostaticaly using liquid aluminium in the temperature of 950 degrees centigrade (1223 K). The X-ray diffraction have been used to identify the phase components of the sinters. The structure of the sinters have been observed using scanning electron microscope. The hardness values have been obtained by Vicker's test. Findings: The mechanically alloyed powder has consisted of about 94 wt.% of austenite, 5 wt.% of ferrite and not more than 1 wt.% of not alloyed molybdenum. Two kinds of sinters have been produced, one kind made of pure 316L powder, second one obtained with aluminium infiltration within the volume of the sinters. The observed porosity of the sinters has depended on the applied pressing conditions strongly, mainly on the value of cold isostatic pressure. The hardness of the first kind of sinters have achieved a value of 380 HV (98N), the hardness of the second kind - more than 400 HV (98N). Practical implications: The Al infiltrated sinter has been proposed as a material for a part of Diesel engine. As an example, a part of a fuel injection has been produced. Originality/value: The nanocrystalline 316L powder has been obtained using mechanical alloying process. The original method of hot isostatic pressing in liquid aluminium has been proposed. This method enables to produce infiltrated sinters with low porosity and high hardness values.

5

Właściwości i zastosowanie spiekanych stali nierdzewnych.

Biało D., Kulesza T., Ludyński Z., Proć T., Kulszewicz I.

Mechanik

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1998

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R. LXXI, nr 1

31-34

PL

Charakterystyka typowych proszków stali nierdzewnych stosowanych do wytwarzania elementów maszyn oraz najczęściej stosowane metody formowania: prasowanie matrycowe, formowanie wtryskowe, prasowanie na gorąco i prasowanie izostatyczne na gorąco. Specyfika spiekania wyrobów ze stali nierdzewnych, właściwości tych stali oraz obszerne zestawienie ich zastosowań w różnych dziedzinach techniki.

EN

Characteristic of typical powders of rustless steel intended for making machine elements and commonest forming methods: die pressing, injection moulding, hot pressing. Specificity of the sintering of rustless steel products, properties of such steels and a comprehensive list of their applications in different fields of technology.