|
| 7075超高强铝合金脉冲MIG焊接头组织与性能 |
| Microstructure and Properties of 7075 High Strength Al-alloy Pulsed MIG Welding Joints |
| Received:September 11, 2017 Revised:November 10, 2017 |
| DOI：10.3969/j.issn.1674-6457.2017.06.029 |
| 中文关键词: 7075铝合金 脉冲MIG焊 微观组织 力学性能 |
| 英文关键词: 7075 Al-alloy pulsed MIG welding microstructure mechanical properties |
| 基金项目: |
| Author Name | Affiliation | | CHEN Da-jun | Southwest Institute of Technique and Engineering, Chongqing 400039, China | | LI Zhong-sheng | Southwest Institute of Technique and Engineering, Chongqing 400039, China | | DAI Ming-hui | Southwest Institute of Technique and Engineering, Chongqing 400039, China | | FU Yang-fan | Southwest Institute of Technique and Engineering, Chongqing 400039, China | | DAI Ye | Southwest Institute of Technique and Engineering, Chongqing 400039, China |
|
| Hits: 3823 |
| Download times: 3553 |
| 中文摘要: |
| 目的 研究7075铝合金脉冲MIG焊接头组织与性能。方法 通过对5 mm厚7075铝合金进行脉冲MIG焊接，采用OM、SEM、万能试验机及显微硬度仪对接头的微观组织及性能进行表征。结果 7075铝合金脉冲MIG焊接头中，无咬边、裂纹、未熔合等焊接缺陷；接头显微硬度分布呈现中间低两头高的特征，平均抗拉强度高达370 MPa以上，达到母材强度的70%以上；焊缝区为晶粒尺寸约25~45 μm的等轴晶组织，靠近熔合线的焊缝区域为柱状晶组织，热影响区靠近熔合区一侧为类似等轴晶组织；焊缝区为韧窝断裂，热影响区为脆性沿晶断裂和少量韧窝断裂的混合断裂模式。结论 采用脉冲MIG焊技术可实现7075铝合金的高强连接。 |
| 英文摘要: |
| The paper aims to study the microstructure and properties of 7075 Al-alloy pulsed MIG welding joints. The 5 mm thick 7075 Al-alloy was welded with pulsed MIG welding, and the characterization of the microstructure and properties of 7075 Al-alloy pulsed MIG welding joints was studied with OM, SEM, universal testing machine and microhardness tester. The undercut crack and incomplete fusion were not found in zone of 7075 Al-alloy pulsed MIG welding joints. The microhardness curve of welding joint was low in the middle and high at the two ends. The average tensile strength of the joints in the experiment was higher than 370 MPa, which was over 70% of the base metal tensile strength. The microstructure of weld zone was isometric crystal of grain size of 25~45 μm; weld zone near fusion line was columnar crystal; and heat affected zone near fusion line was similar isometric crystal. Weld zone shows dimple fracture and the heat affected zone characterize with brittle intergranular fracture and a small amount of dimple fracture. 7075 Al-alloy could be welded with high-strength by pulsed MIG welding. |
|
View Full Text
View/Add Comment Download reader |
| Close |
渝公网安备 50010702501719号