七、X射线应力测定
七、X射线应力测定
General stress/strain effects Chinese magic mirror in Han Dynasty(200 B.C.-200 A.D.) The first deliberate use of residual stresses and strains. 2
General stress/strain effects 2 Chinese magic mirror in Han Dynasty (200 B.C. – 200 A.D.) The first deliberate use of residual stresses and strains
Channel crack Low-k dielectric Copper (OSG) interconnect line KFAB1.0kV4.4mm×15.0ksEU)5/19/2000 3.00um Channel cracking,a fracture mode in which through-film cracks propagate in the film due to a tensile residual stress OGS:organosilicate glass The above picture is of a new pressure vessel that failed during its hydraulic test.The vessel had been stress relieved,but some parts of it did not reach the required temperature and consequently did not experience adequate tempering.This coupled with a small hydrogen crack,was sufficient to cause catastrophic failure under test conditions.It is therefore important when considering PWHT or its avoidance,to ensure that all possible failure modes and their consequences are carefully considered before any action is taken 3
3 Channel cracking, a fracture mode in which through-film cracks propagate in the film due to a tensile residual stress OGS: organosilicate glass The above picture is of a new pressure vessel that failed during its hydraulic test. The vessel had been stress relieved, but some parts of it did not reach the required temperature and consequently did not experience adequate tempering. This coupled with a small hydrogen crack, was sufficient to cause catastrophic failure under test conditions. It is therefore important when considering PWHT or its avoidance, to ensure that all possible failure modes and their consequences are carefully considered before any action is taken
七、X射线应力分析 ·应力-应变的基本特征 ·宏观应力 ·微观应变/应力
七、X射线应力分析 • 应力-应变的基本特征 • 宏观应力 • 微观应变/应力 4
应力-应变间关联 ·应力o(stress)→应变&(strain)→晶面间 Ad (change of lattice spacing) △d △d △λ△0cos0 d d sinθ ·线弹性假设下，Hook'slaW:o=Eor=G 通过测定物体中的应变从而确定其应力大 小。 5
应力-应变间关联 • 应力 (stress) 应变 (strain) 晶面间 距d (change of lattice spacing) • 线弹性假设下，Hook’s law: =E or =G • 通过测定物体中的应变从而确定其应力大 小。 sin cos d d d d ~ 5