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Investigations of the Effect of Heat Treatment and Plastic Deformation Parameters on the Formability and Microstructure of AZ91 Alloy Castings

Majerski Krzysztof, Siemionek Ewa, Szucki Michał, Surdacki Piotr

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no 1

1--9

EN

The article discusses the influence of heat treatment and metal forming parameters on formability and the structure of the AZ91 cast magnesium alloy. The aim of the article is to determine the optimal parameters of homogenization and plastic deformation of sand castings made of the AZ91 alloy in order to improve their properties and structure. In this study, sand castings made from the AZ91 alloy were examined. In the first stage, the castings were homogenized at: 385°C, 400°C, 415°C and 430°C with argon as a shielding gas for 24 hours and then quenched. Subsequently the upsetting tests were conducted at 380 C; 400 C; 420 C; 440 C for two deformation values: ε=0.7 and ε=1.1. After upsetting, the samples were water- and air-cooled. At this stage, a visual assessment was made and samples without cracks were subjected supersaturation at 415 C for 6 h, and artificial aging at 175 C for 24 h. Vickers microhardness tests and microstructure assessment were carried out, at individual stages of testing. Based on the results obtained from the upsetting, structure and hardness tests, the most favorable homogenisation and plastic deformation conditions were determined for AZ91 alloy sand castings. The best results are achieved by homogenizing sand castings at 415 °C for 24 h. Among the tested parameters for conducting metal forming processing in the range of 380-440 °C and deformation values: ε=0.7 and ε=1.1, forging of sand-cast AZ91 magnesium alloy at 420 °C and deformation of ε=0.7 with water cooling seems to be the most favourable. The final heat treatment applied after the deformation process consists of supersaturation at 415 °C for 6 hours water quenching as artificial aging at 175 °C for 24. This combination of heat and plastic treatment parameters of castings allows for improvement of the structure and properties of sand castings made of the AZ91 alloy.

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Review of Magnesium Alloys Used in the Manufacture of Wheels for Light Vehicles

Siemionek Ewa, Majerski Krzysztof, Surdacki Piotr, Novakova-Marcincinova Ema

Advances in Science and Technology. Research Journal

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2023

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Vol. 17, no 6

245--253

EN

This article provides an overview of the materials used to manufacture magnesium wheels for light vehicles. The analysis was conducted with the aim of developing a new, efficient technology for molding magnesium alloy wheels for light vehicles from preforms cast into metal molds. The knowledge accumulated so far on materials and their properties for the production of magnesium wheels will allow the design of a new technology for molding rims from materials of superior quality and durability. Currently, magnesium wheels are mainly produced from cast magnesium alloys and magnesium alloys for forming. Cast magnesium alloys used for magnesium wheels include AZ91, AM50, AM60, AE44, ZK61, ZE41, EZ33, EQ21, WE43 and the newly developed Mg-2.96Nd-0.21Zn-0.39Zr alloy. Magnesium metal-forming alloys used for magnesium wheels include AZ31, AZ61, AZ80 and ZK30, ZK60. The study includes an analysis of their properties and application examples.

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The impact of ignition system damage on the emission of toxic substances in a spark-ignition internal combustion engine

Dziubiński Mieczysław, Siemionek Ewa, Drozd Artur, Ścirka Michał, Kiszczak Adam, Sobota Krzysztof

Combustion Engines

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2019

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R. 58, nr 4

86--92

EN

The article discusses the impact of ignition system damage on the emission of toxic subcategories in a spark-ignition internal combustion engine. The aim of the work was to develop an analytical model of ignition system diagnostics, test performance and comparative analysis of the results of simulations and experiments. The model developed allows to analyse the basic parameters of the ignition system affecting the content of toxic substances in the exhaust. Experimental tests were carried out using the MAHA MGT5 exhaust gas analyser for four different combustion engines fueled with petrol at various operating conditions. During the tests, the content of toxic substances in the exhaust gas of a properly working engine and the engine working with damage to the ignition system were registered. The tests will be used to assess the impact of the damage of the spark-ignition engine on the emission of individual components of toxic fumes.

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Analysis of the impact of damage to the injection system on the emission of toxic substances in a spark-ignition internal combustion engine

Dziubiński Mieczysław, Siemionek Ewa, Drozd Artur, Żur Paweł, Ścirka Michał, Tatarynow Dawid

Combustion Engines

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2019

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R. 58, nr 4

112--118

EN

The article presented analyses the impact of damage to the injection system on the emission of toxic subsumes in a spark-ignition internal combustion engine. The work focuses on the basic elements of the injection system, which include injectors, throttle position sensor, coolant temperature sensor and lambda sensor. In addition, a catalytic reactor has been included in the context of its direct cooperation with the injection system under set conditions. The toxicity of exhaust gases of different spark-ignition engines fueled with petrol or gas in determined operating conditions using the MAHA MGT5 exhaust gas analyser was tested. The content of toxic substances in the exhaust gases was recorded for the correct settings of the injection system and for the engine working with damage to this system. The tests carried out will allow to assess the impact of the damage of the injection system on the toxicity of exhaust gases.