采用钨极氩弧焊对ZM6铸造镁合金进行焊接,并对其进行了T6热处理,利用光学显微镜及扫描电镜对焊后及热处理后的焊接接头显微组织进行观察,对试样进行显微硬度和抗拉强度测试.结果表明:经过540℃固溶处理后,晶界处的化合物已基本固溶到基体.经200℃时效16 h后,出现3种析出相,并且焊缝及母材显微硬度均达到最大值,分别为85HV和81HV.热处理后拉伸试验断裂位置在熔合区附近,抗拉强度达到260 MPa,较未热处理的160 MPa有较大提高.热处理后拉伸断口形貌呈现出两个不同的区域,分别为解理和韧窝?解理混合断裂.
@@@@Tungsten inert gas welds were performed on cast ZM6 magnesium alloy and T6 heat treatment was carried out followed. The microstructures of welded joints and heat treated joints were investigated by optical and scanning electron microscopy. The microhardness and tensile strength were determined. The results demonstrate that after solution treatment at 540℃, the compounds in the grain boundary dissolve into the matrix. After aging at 200℃for 16 h, three kinds of precipitates appear. The microhardness of weld seam and base metal reaches the maximum, which are 85HV and 81HV, respectively. The fracture locations of heat treated specimens in the tensile test are near the fusion zone. The heat treated specimens show the ultimate tensile strength of 260 MPa. Compared with not heat-treated of 160 MPa, the tensile strength of heat treated specimens is improved significantly. The tensile fracture of heat treated specimen surface shows two different areas, which are cleavage fracture and dimple-cleavage mixed fracture, respectively.
参考文献
| [1] | Shigeharu Kamado;Junichi Koike;Katsuyoshi Kondoh .Magnesium Research Trend in Japan[J].Materials Science Forum,2003(Pt.1):21-33. |
| [2] | KOJIMA Y;AIZAWA T;HIGASHI K;SHIGEHARU K .Automotive applications of magnesium alloys[J].Materials Science Forum,2003,419:67-74. |
| [3] | Liming Liu;Changfu Dong .Gas tungsten-arc filler welding of AZ31 magnesium alloy[J].Materials Letters,2006(17/18):2194-2197. |
| [4] | Investigation of the corrosion behaviour of laser-TIG hybrid welded Mg alloys[J].Corrosion Science: The Journal on Environmental Degradation of Materials and its Control,2010(9):P.3078. |
| [5] | G. Padmanaban .Fatigue performance of pulsed current gas tungsten arc, friction stir and laser beam welded AZ31B magnesium alloy joints[J].Materials & design,2010(8):P.3724. |
| [6] | Nan Xu;Jun Shen;Weidong Xie;Linzhi Wang;Dan Wang;Dong Min .Abnormal distribution of microhardness in tungsten inert gas arc butt-welded AZ61 magnesium alloy plates[J].Materials Characterization,2010(7):713-719. |
| [7] | Dong Min;Jun Shen;Shiqiang Lai .Effect of heat input on the microstructure and mechanical properties of tungsten inert gas arc butt-welded AZ61 magnesium alloy plates[J].Materials Characterization,2009(12):1583-1590. |
| [8] | 柯黎明,邢丽,徐卫平.AZ81A镁合金焊接接头的组织与性能[J].材料工程,2005(01):41-44. |
| [9] | ZHOU W;LONG T Z;MARK C K .Hot cracking in tungsten inert gas welding of AZ91D Mg alloy[J].Materials Science and Technology,2007,23(11):1293-1299. |
| [10] | MUNITZ A;COTLER C;STERN A;KOHN G .Mechanical properties and microstructure of gas tungsten arc welded magnesium AZ91D plates[J].Materials Science and Technology,2001,302(01):68-73. |
| [11] | Tianping Zhu;Zhan W. Chen;Wei Gao .Incipient melting in partially melted zone during arc welding of AZ91D magnesium alloy[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2006(1/2):246-252. |
| [12] | 陈振华.耐热镁合金[M].北京:化学工业出版社,2007:517-518. |
| [13] | 文丽华 .固相再生ZM6耐热镁合金组织和性能研究[D].哈尔滨:哈尔滨理工大学,2009. |
| [14] | ROKHLIN L L.Magnesium alloys containing rare earth metals[M].San Diego:Taylor and Francis,2003:31-32. |
| [15] | 杜建锋 .ZM6合金组织及高温性能研究[D].哈尔滨工业大学,2006. |
| [16] | 王晓芳,孙扬善,王奇,薛烽,白晶,薛山,陶卫建.Mg-2Nd合金的组织与力学性能[J].中国有色金属学报,2007(06):927-933. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%