辉长岩脆-塑性转化及其影响因素的高温高压实验研究

本文利用高温高压多功能三轴实验装置,以NaCl为固体围压传压介质,在围压为450MPa~800MPa,温度区间为600℃~1150℃和应变速率为1×10-4~3.125×10-6/s条件下,对攀枝花辉长岩进行了流变学实验研究。实验结果表明,辉长岩围压在450MPa~800MPa条件下,温度在600℃时为脆性变形,700℃~850℃时为半塑性流动,含微破裂,大于900℃时为塑性流动。辉长岩的脆-塑性转化温度为700℃~900℃,主要影响因素为温度、围压和应变速率,同时存在双相流变学问题。 

AN EXPERIMENTAL STUDY ON THE BRITTLE-PLASTIC TRANSITION IN GABBRO

In this paper,an experimental study of brittle-ductile transition in Panzhihua fine grained gabbro was performed under a Griggs-type apparatus with NaCl as the confining pressure medium. Experiments were conducted in conditions of:450MPa~800MPa confining pressure,600℃~1150℃ temperature,and 1×10-4~3.125×10-6/s strain rate.The results of experiments show that the deformation of the gabbro is brittle fractures at temperature 600℃,semibrittle flow at 700℃~850℃,and plastic flow at temperature higher than 900℃.The temperature of brittle plastic transition is 700℃~900℃ at the confining pressure 450MPa~800MPa.The major factors that influence the brittle-plastic transition in the gabbro are temperature and strain rate,and the influence of confining pressure is secondary.