6156铝合金的人工时效与蠕变时效研究

Investigation on Artificial Aging and Creep Aging of 6156 Aluminum Alloy

采用光学显微及透射电子显微、维氏硬度、拉伸力学性能、电导率测试等技术,研究了试验6156铝合金的人工时效与蠕变时效强化规律与微观组织特征。结果表明,在本文试验的温度(155～175℃)-应力(0～200MPa)时-间(8～14h)范围内,采用不同制度的人工时效和蠕变时效样品的力学性能相差不大,但蠕变时效的析出相数量增多、尺寸变小,力学性能与电导率指标均呈升高趋势。蠕变时效过程中,蠕变第一阶段变形量占总变量的85%以上,增加蠕变应力对蠕变第一阶段变形量的影响十分明显。该合金蠕变时效温度与应力对强度峰值影响不明显,但显著影响蠕变变形量,适合于构件蠕变时效成形。

The characteristics of strengthening and microstructure of 6156 Aluminum alloy under the conditions of artificial aging（AA） and creep aging（CA） were studied by the techniques of optical microscopy（OM）,transmission electron microscopy（TEM）,Vicker hardness test,tensile properties test and electric conductivity test.The results show that the peak mechanical properties of the samples treated by various AA or CA schemes have little difference within scales of temperature（155～175℃）-loading stress（0～200MPa）-time（8～14h）.However,the amount of precipitates increased and the sizes of them decreased,and then both the mechanical property and electrical conductivity of the CA samples increased as compared with that of the AA samples.The primary creep strains accounted is more than 85% of the total amount strains,and increased extremely with the loading stresses increased.The peak mechanical properties of the CA samples were not sensitive to the testing temperatures and stresses,but the creep strains of them were sensitive to the loading stresses.This implies that the 6156 Aluminum alloy is suitable to creep age forming（CAF） of component.