Research progress of hot crack in fusion welding of advanced aeronautical materials

Abstract

The high fusion welding hot cracking sensibility of the next-generation alloy is the key technological difficulty that hinders its widely application in the aeronautic and astronautic industry. A critical review of the fusion welding hot cracking from the perspective of basic mechanism and the experimental research of typical materials was presented in this article. The fusion welding hot cracking phenomena include solidification cracking (occurs within the fusion zone) and liquidation cracking (occurs at the interface between fusion zone and partial melting zone). The formation factors of the fusion welding hot cracking include alloying composition, welding thermal cycle and thermal stress. Based on the comprehensive understanding of the formation mechanism of the fusion welding hot cracking, the relative research progress in the field of aluminum alloys, magnesium alloys, advanced high strength steel and nickel alloys was summarized. The establishment of the quantitative criterion that involves the effects of complicated multi-component and the morphology of the dendrite on the cracking sensibility is the key development direction. Optimizing the alloying composition of the base metal or filler metal, adding nucleanting agent or auxiliary facilities are the practical method for restraining the fusion welding hot cracking. Conducting the research on the mechanism and restraining method of the fusion welding hot cracking helps to solve the difficulty of the next generation alloys processing, which can realize their application in the field of aeronautic and astronautic industry.

Keywords

• hot cracking
• aluminum alloy
• magnesium alloy
• high strength steel
• ni-based superalloy