微觀結(jié)構(gòu)與力學(xué)性能的影響
(西北工業(yè)大學(xué) 材料科學(xué)與工程學(xué)院, 西安 710072)
摘 要: 采用透射電鏡和扭轉(zhuǎn)試驗(yàn)研究了外加靜電場(chǎng)對(duì)LY12CZ合金摩擦焊接頭焊合區(qū)顯微結(jié)構(gòu)和力學(xué)性能的影響。 結(jié)果表明, 靜電場(chǎng)提高了摩擦焊接頭焊合區(qū)的合金元素固溶程度, 使s′相析出數(shù)量增多, 并以小尺寸彌散分布； 同時(shí), 電場(chǎng)的激活作用降低了焊合區(qū)晶粒內(nèi)的位錯(cuò)密度, 減少了位錯(cuò)纏結(jié)程度, 增加了位錯(cuò)的可動(dòng)性。 因而, 合適的靜電場(chǎng)可以加強(qiáng)摩擦焊接過(guò)程中晶界運(yùn)動(dòng)在協(xié)調(diào)焊合區(qū)金屬塑性變形方面的作用, 提高焊接接頭的塑性。
關(guān)鍵字: 電塑性效應(yīng)； 摩擦焊接； LY12CZ合金； 顯微結(jié)構(gòu)； 力學(xué)性能
mechanical properties of
friction welding joint of LY12CZ alloy
（College of Materials Science and Engineering,
Northwestern Polytechnical University, Xi'an 710072, China）
Abstract:By means of TEM and the torsion test, the microstructure and the mechanical properties of the friction welding joint of LY12CZ alloy in the presence of the electrical field were studied. The results show that the external electric field increases the solubility of the alloy elements in the weld zone of the friction welding joint, promotes the formation of the precipitation phases with a small size and a dispersion distribution. Meanwhile, the dislocation density in the grain and the entwining degree of dislocation decrease in the presence of the electric field. Hence the external electric field harmonizes the plastic deformation in the weld zone, and improves the plasticity of the friction welding joint.
Key words: electroplastic effect； friction welding； LY12CZ alloy； microstructure； mechanical properties
