由压痕蠕变试验确定材料的蠕变性能参数

研究由平头压痕蠕变试验来确定受压材料蠕变性能参数的可行性。利用有限元蠕变分析确定在定压痕应力下的压痕蠕变率,重点放在稳定压痕蠕变率和受压材料蠕变性能参数的关系上。详细地研究了压头形状、大小和宏观约束对压痕蠕变响应的影响:当压头的尺寸和受压材料为同一数量级时,宏观约束将有十分明显的影响。提出两种方法来由压痕蠕变试验来确定受压材料蠕变性能参数,并给出了算例,结果有利于准确认识平头压痕蠕变试验,从而拓宽其应用范围。

Determination of Creep Parameters from Indentation Creep Experiments

The possibilities of determining creep parameters for a simple Norton law material are explored from indentation creep testing.Using creep finite element analysis the creep indentation test technique is analyzed in terms of indentation rates at constant loads.Emphasis is placed on the relationships between the steady creep behavior of indentation systems and the creep property of the indented materials.The role of indenter geometry, size effects and macroscopic constraints is explicitly considered on indentation creep experiments.The influence of macroscopic constraints from the material systems becomes important when the size of the indenter is of the same order of magnitude as the size of the testing material.Two methods have been presented to assess the creep property of the indented material from the indentation experimental results on the single-phase-material and two-phase-material systems.The results contribute to a better mechanical understanding and extending the application of indentation creep testing.