AZ-Mg Alaşımlarının Katılaşma Çatlama Duyarlılığına Karşı Dolgu Metal ve Alaşım Elamanlarının Etkilerinin Tahmin Edilmesi

Abstract

Katılaşma çatlağı, magnezyum (Mg) alaşımlarının kaynağı için kaygı verici bir unsurdur. Maksimum │dT/d(fS)1/2│, bir indeks olarak Pandat termodinamik yazılımı ile alüminyum ve çinkonun başlıca alaşım elementlerinin olduğu AZ-Mg ark kaynaklarının katılaşma çatlama duyarlılığını tahmin etmede kullanılmıştır. Bu indeksle AZ101 magnezyum kaynak telinin ticari olarak temin edilebilir AZ31, AZ61 ve AZ91 Mg alaşımlarının çatlak duyarlılığını azaltmaya etkisi araştırılmıştır. AZ101 Mg kaynak teli, üç alaşımın da katılaşma çatlağının duyarlılığının azaltılmasında etkili bulunmuştur. Alüminyum ve çinkonun AZ-Mg alaşımlarının katılaşma çatlağına olan etkisi çatlak indeksi ve Pandat ile Scheil katılaşma modeli esas alınarak tahmin edilmiştir. İndekse dayalı tahminler AZ-Mg alaşımlarının deneysel çatlak duyarlılığı verileri ile karşılaştırılmış ve hem tahminlerin hem de deneysel verilerin genel trendinin birbiriyle uyumlu olduğu görülmüştür. Tahminler, katılaşma çatlağı için önerilen kriter ışığında açıklanmıştır.

Keywords

• katılaşma çatlağı
• kaynak edilebilirlik
• magnezyum alaşımları
• çatlak duyarlılığı tahminleri

Estimating the Effects of Filler Metal and Alloying Elements for Against Solidification Cracking Susceptibility of AZ-Mg Alloys

Abstract

Solidification cracking is a concern for welding magnesium (Mg) alloys. An index, the maximum │dT/d(fS)1/2│,was used with the thermodynamic software Pandat to make solidification cracking susceptibility predictions for AZ-Mg arc welds which have the main alloying elements of aluminum and zinc in the magnesium matrix. The effect of AZ101 magnesium filler on reducing crack susceptibility of commercially available AZ31, AZ61 and AZ91 Mg alloys was investigated with the crack susceptibility index. The filler metal AZ101 Mg alloy was found effective to reduce the susceptibility of all the three AZ-Mg alloys to solidification cracking. The influence of the amount of aluminum and zinc in the AZ-Mg alloys on the crack susceptibility was predicted using the cracking index and Pandat based on Scheil solidification model. The predictions based on the index were compared to the experimental crack susceptibility data of the AZ-Mg alloys, and it was seen that the general trend of both predictions and the reported data was consistent with each other. The predictions were explained in the light of the criterion proposed for solidification cracking.

Keywords

• solidification cracking
• weldability
• magnesium alloys
• crack susceptibility predictions

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