Correlation between the ultimate tensile strength and the hardness of aluminum alloy 2219 and its joints welded with a variable-polarity tungsten electrode in inert gases (VPTIG) and by friction stir welding (FSW) is studied. The yield strength (σy) and the ultimate strength (σr) of the base metal, the microhardness and the strain hardening coefficient of the welded joints are determined. Linear correlation dependences are suggested for the yield strength, the ultimate strength, and the hardness. The strain hardening coefficient and the ratio σy/σr are shown to be correlated. The correlations are based on the measurement of microhardness and can be used for predicting the strength of fusion zones and heat-affected zones of aluminum alloys joined by a narrow weld.

中文翻译：

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2219铝合金及其焊接接头抗拉强度与硬度的相关性研究

研究了用可变极性钨电极在惰性气体中（VPTIG）和搅拌摩擦焊（FSW）焊接的2219铝合金及其接头的极限抗拉强度和硬度之间的相关性。确定母材的屈服强度（σy）和极限强度（σr），焊接接头的显微硬度和应变硬化系数。建议屈服强度、极限强度和硬度具有线性相关性。应变硬化系数和比值σy/σr 显示为相关。相关性基于显微硬度的测量，可用于预测由窄焊缝连接的铝合金的熔合区和热影响区的强度。