Reducing welding hot cracking of high-strength novel Al–Mg–Zn–Cu alloys based on the prediction of the T-shaped device

ABSTRACT

The higher hot cracking tendency during fusion welding in traditional high-strength 7000 series alloys has been an obstacle for its further application. In this study, the cracking susceptibility can be suppressed by fabricating Al–Mg–Zn–Cu alloys with Zn/Mg≤1 and Cu/Mg≤0.25 while simultaneously maintaining the high strength. A T-shaped device combined with non-equilibrium solidification is developed to simulate the solidification during fusion welding, and it is effective to predict the shrinkage load, temperature and solid fraction. The effect of solidification temperature range, the amount of eutectics at the terminal stage of solidification and the shrinkage load during solidification on the hot cracking susceptibility are discussed in detail.

KEYWORDS:

• Hot cracking
• Al alloys
• fusion welding
• Shirinkage load
• solid fraction
• non-equilibrium solidification
• microstructure

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Major State Research and Development Program of China under Grant Number 2016YFB0300801; the National Natural Science Foundation of China under Grant Numbers 51571013 and 51971019.