Effect of heat treatment on chemical and microstructural heterogeneity of magnesium alloy AZ61

• Autorzy: Horynova M. , Dolezal P. , Janova D. , Gejdos P.
• Konferencja: Międzynarodowe Sympozjum Metody oceny struktury oraz własności materiałów i wyrobów (XXV ; 12-14.10.2010 ; Turawa, Polska)
• Języki publikacji: EN

Abstrakty

EN

The contribution is focussed on the assessment of the influence of a heat treatment of magnesium alloy AZ61 on its chemical and microstructural heterogeneity. The experimental material was manufactured by squeeze casting method using alternative two-stage casting. The microstructure of the alloy in as cast state composed of ä solid solution, Mg17Al12 intermetallic phase and minor phases based on Mn. The heat treatment applied on the alloy was the solution annealing at the temperature of 380 °C and with graded dwell from 1 to 8 hours. Chemical etching was employed in order to estimate the micro-segregation of the elements in the matrix qualitatively and to discern the phases in the microstructure. The differences in matrix heterogeneity between the as cast state and after annealing were documented by means of light microscopy. Differences in etching between the central part and periphery of the crystalline units are apparent in the metallographic images. Quantitative assessment of chemical heterogeneity was done by mapping and local chemical microanalyses. It was found by mapping that with increasing delay at annealing temperature the Mg17Al12 intermetallic phase gradually dissolves and the micro-heterogeneity of each element decreases. Chemical heterogeneity of particular elements was measured by local chemical analysis and the intensity of chemical micro-heterogeneity of each sample was further expressed using effective distributive coefficients. It follows from the results that the solution treatment of the AZ61 magnesium alloy leads to diminishment of the chemical and microstructural heterogeneity. It also follows from the results presented that the combination of metallographic analyses with X-ray spectral analysis of wave- or energy-dispersive type is advantageous for the quantitative assessment of micro-segregation of elements in the matrix of magnesium alloys.

Słowa kluczowe

EN

magnesium alloy AZ61; chemical and microstructural heterogeneity; chemical heterogeneity

• Wydawca: Oficyna Wydawnicza Politechniki Opolskiej
• Czasopismo: Zeszyty Naukowe. Mechanika / Politechnika Opolska
• Rocznik: 2010
• Tom: z. 97
• Strony: 51--52
• Opis fizyczny: rys., tab. wykr.

Twórcy

autor

Horynova M.

autor

Dolezal P.

autor

Janova D.

autor

Gejdos P.

• Brno University of Technology, Faculty of Mechanical Engineering, Czech Republic