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Effect of intensive cooling of alloy AM60 with chromium and vanadium additions on cast microstructure and mechanical properties

Rapiejko C., Pisarek B., Pacyniak T.

Archives of Metallurgy and Materials

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2017

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Vol. 62, iss. 1

309--314

EN

The work presents the results of the investigations of the effect of intensive cooling of alloy AM60 with additions of chromium and vanadium on the microstructure and mechanical properties of the obtained casts. The experimental casts were made in ceramic moulds preliminarily heated to 180°C, into which alloy AM60 with the additions was poured. Within the implementation of the research, a comparison was made of the microstructure and mechanical properties of the casts obtained in ceramic moulds cooled at ambient temperature and the ones intensively cooled in a cooling liquid. The kinetics and dynamics the thermal effects recorded by the TDA method were compared. Metallographic tests were performed with the use of an optical microscope and the strength properties of the obtained casts were examined: UTS(Rm), elongation (A%), and HB hardness.

2

Effect of Cr and V Alloy Additions on the Microstructure and Mechanical Properties of Am60 Magnesium Alloy

Rapiejko C., Pisarek B., Pacyniak T.

Archives of Metallurgy and Materials

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2014

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Vol. 59, iss. 2

761--765

EN

The paper presents the results of the investigation of the effect of Cr and/or V alloy additions on the microstructure and mechanical properties of the magnesium AM60 alloy. The examinations are performed within the frames of a project aiming at the elaboration of an experimental and industrial technology of producing constructively complex elements of machines and devices made of magnesium alloys with the method of investment casting. It has been proven that small numbers of Cr and V alloy additions improve the strength properties: Rm, A%, and the hardness HB of the obtained casts. The experimental casts were made in ceramic molds.

PL

W pracy przedstawiono wyniki badań wpływu dodatków stopowych Cr i/lub V na mikrostrukturę oraz właściwości mechaniczne stopu magnezu AM60. Badania prowadzone są w ramach projektu, którego celem jest opracowanie technologii doświadczalnej i przemysłowej wytwarzania złożonych konstrukcyjnie elementów maszyn i urządzeń ze stopów magnezu metodą wytapianych modeli. Wykazano, że niewielkie ilości dodatków stopowych Cr i V poprawiają właściwości wytrzymałościowe: Rm, A%. oraz twardość HB otrzymanych odlewów. Odlewy doświadczalne wykonano w formach ceramicznych.

3

Cooling curve and microchemical phase analysis of rapidly quenched magnesium AM60B and AE44 alloys

Gesing A.J., Sokołowski J. H., Marchwica P.C., Blawert C., Jekl J., Kozdras M., Kasprzak M., Wood J.

Journal of Achievements in Materials and Manufacturing Engineering

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2013

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Vol. 58, nr 2

59--73

EN

Purpose: Development of the understanding of the effect of the solidification rate with the alloy microstructures for the structural AM60B and the creep resistant AE44 Mg casting alloys. Design/methodology/approach: Tubular macro test samples of magnesium alloys AM60B and AE44 were melted and quenched at maximum instantaneous cooling rates ranging from -5°C/s to -500°C/s in the Universal Metallurgical Simulator and Analyzer (UMSA) Technology Platform while recording the temperature-time traces. Such rapid cooling rates are typical in water-cooled dies used in high pressure die casting (HPDC). Characteristic reactions on these curves corresponding to the formation of individual phases during solidification were quantified based on cooling curve analysis combined with metallographic and micro-chemical analysis, with the aid of literature data. Findings: The results indicate that these phases, their size and location in the microstructure, their chemistry and their relative proportions all change in response to the increase in the cooling rate. The results are drastically different for the two alloy systems studied. Solidification of AM60B alloy yields small, equiaxed α-Mg rosettes whose size is mostly independent of the cooling rate. These rosettes nucleate heterogeneously on Al8Mn5 phases that are first to form, and are surrounded by the eutectic structure of Mg and Mg17Al12. In contrast, the AE44 has very large α-Mg grains at all cooling rates. These grains are filled with Al11RE3 platelets or dendrites. Results suggest that the Al11Re3 phase is completely ineffective in heterogeneous nucleation of α-Mg grains. Originality/value: In this research the authors significantly extended the thermal analysis methodology. The specific results obtained on the structural and creep-resistant Mg casting alloys are of significant value to the development of automotive light metal structures and power train components as well as further development of solidification codes for the commercial HPDC process.