BFe10-1-1白铜FSW接头组织和力学性能研究

Study on Microstructure and Mechanical Properties of FSW joint of BFe10-1-1 Copper

采用搅拌摩擦焊对4 mm厚的BFe10-1-1铜合金进行焊接,研究了焊接参数对接头组织和力学性能的影响规律。结果发现:在机械力和焊接热循环的作用下焊缝金属达到塑性状态,形成3个不同的区域:焊核区,热机影响区,热影响区。随着旋转速度的增加,接头的强度呈现出先升高后降低的趋势,最高可达母材的93.8%,断口均具有韧性断裂的特征。接头横截面中显微硬度大致呈W型分布,焊核区硬度最高,热影响区的硬度最低。不同区域的低温冲击试验表明,在-20~-100℃之间,搅拌摩擦焊接头各区域冲击韧性变化很小,焊核区冲击韧性最高,热机影响区的冲击韧性最小,表明BFe10-1-1搅拌摩擦焊接头具有良好的低温冲击性能。

Friction stir welding was used to weld 4 mm thickness BFe10-1-1 copper alloy. The effects of welding parameters on the microstructure and the mechanical properties of the joints were investigated. The results show that the weld metal reaches plastic state under the action of mechanical force and welding thermal cycle. It forms three different regions: the welding nugget zone(NZ), the thermo-mechanically affected zone(TMAZ), and the heat affected zone(HAZ).With the increase of rotating speed, the strength of the joint increases first and then decreases, The highest strength is up to93.8% that of the base metal, and the fracture surface is characterized by ductile fracture. The distribution of the microhardness of the cross section of joint is W shape, the microhardness of NZ is the highest and the microhardness of HAZ is the lowest. The low-temperature impact test of different areas shows that the impact toughness of FSW joint varies little in each area at-20--100℃, the impact toughness of the NZ is the highest, and the impact toughness of the HAZ is the smallest, indicating that BFe10-1-1 FSW joint has good low-temperature impact performance.