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Influence of manufacturing technology on tribological properties of A390.0 alloy

Wieszała R., Piątkowski J., Roszak M., Pakieła W.

Journal of Achievements in Materials and Manufacturing Engineering

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2016

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Vol. 77, nr 1

13--17

EN

Purpose: In this paper, results of tribological studies on AlSi17Cu5Mg alloy subjected to a modification (CuP10) and a significant overheating above Tliq are presented, referring them to the starting material. Design/methodology/approach: The influence of the applied technologies on the refinement of the primary crystals of Si was defined by determination of stereological parameters. In case of the overheated alloy, the primary crystals of silicon assume the forms of polygons with sharp edges after the overheating. In practice, it results in a decrease in tribological properties and an increase in the coefficient of friction in relation to the alloy modified with phosphorus. Findings: The result show that all investigated properties were changed. Significant differences between the analyzed specimens were proved in the friction coefficient and in the wear rate of the tested friction connections. Research limitations/implications: The application of modified by CuP10 aluminum alloy allows to reduce the friction coefficient between tested surface and counter-samples and also reduce the wear rate. This property’s causes that this material can be used in many applications where the aim is to reduce friction coefficient and wear rate. Practical implications: Reducing of friction coefficient and increase wear resistance causes that these materials can be used in many applications in the automotive industry such as blocks of engines, cylinders etc. Originality/value: Influence of aluminium modification on chosen tribological properties have been investigated.

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The Study of Phase Transformations of AlSi9Cu3 Alloy by DSC Method

Piątkowski J., Przeliorz R., Gontarczyk A.

Archives of Foundry Engineering

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2016

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Vol. 16, iss. 4

109--112

EN

With the use of differential scanning calorimetry (DSC), the characteristic temperatures and enthalpy of phase transformations were defined for commercial AlSi9Cu3 cast alloy (EN AC-46000) that is being used for example for pressurized castings for automotive industry. During the heating with the speed of 10ºC∙min-1 two endothermic effects has been observed. The first appears at the temperature between 495 ºC and 534 ºC, and the other between 555 ºC and 631 ºC. With these reactions the phase transformation enthalpy comes up as +6 J g-1 and +327 J g-1. During the cooling with the same speed, three endothermic reactions were observed at the temperatures between 584 ºC and 471 ºC. The total enthalpy of the transitions is – 348 J g-1. Complimentary to the calorimetric research, the structural tests (SEM and EDX) were conducted on light microscope Reichert and on scanning microscope Hitachi S-4200. As it comes out of that, there are dendrites in the structure of α(Al) solution, as well as the eutectic (β) silicon crystals, and two types of eutectic mixture: double eutectic α(Al)+β(Si) and compound eutectic α+Al2Cu+β.

3

Typical Quality Defects of the „Alphin” Inserts in Engine Pistons

Piątkowski J., Kamiński P.

Archives of Foundry Engineering

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2015

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Vol. 15, iss. 2 spec.

65--68

EN

In the dissertation, the 5M Method, is being presented, of typical causes and consequences of quality defects of cast-iron inserts „alphin” embedded in aluminum cast. The diffusive connection of those rings, with pistons casts is being used, because of the extreme conditions in which they need to operate in, which are of high temperature and variable thermo-mechanical burden, which are in the working chamber of combustion engine.

4

Chosen Aspects of Quality Defects of ”Alphin” Inserts in Combustions Pistons

Piątkowski J., Kamiński P.

Archives of Foundry Engineering

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2015

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Vol. 15, iss. 4

61--64

EN

The chosen, typical causes of quality defects of cast-iron „alphin” rings embedded in aluminum cast are being presented in this paper. Diffusive joint of those inserts with the pistons casts is being used, due to extreme work conditions of destructive influence of the fuel mix and variable thermo-mechanical loads, which reign in the combustion motor working chamber.