Non-explosive Compound Interface (nanometer) Crystal And Organizations Within The Asb Formation Mechanism

The amorphous and nano-sized grains within the explosive cladding interface were observed by means of transmission electronic microscope (TEM) and high-resolution transmission electron microscope (HRTEM). Their forming reasons were studied using a scientific-calculational software (MATLAB). The microstructure evolution of the nano-sized grains within the adiabatic shear bands was also analyzed quantitatively.The observation by mean of TEM and HRTEM indicated that the amorphous and nano-sized grains co-existed within the TA2/TA2 explosive cladding interface. The size of the nano-sized grains was 2-50 nm. Typical nano-sized grain had a conjunct interface with the matrix, ensuring the high strengthening of the interface. A model for the temperature field was used to quantitatively analyzing the cooling rate. The cooling rate was about 108K/s after the explosive cladding, and it was still about 106K/s when the temperature was cooled to the amorphous phase transition temperature (Tg). The high cooling rate, high pressure and high shearing stress were all advantageous factors to form amorphous phase.TEM observation showed that the center of the adiabatic shear band (ASB) was composed of recrystallized nano-grains (about 30-70 nm in diameter). A Rotational Dynamic Recrystallization (RDR) mechanism which based on mechanics assistance can well explain the microstructure evolution within the ASB. The microstructure evolution of nano-sized grains within ASB during the deformation and cooling stage was analyzed quantitatively by combining thermal-mechanics and recrystallization kinetics with microstructure evolution.By the law of conservation of energy, an equation was proposed to calculate the subgrain size during the microstructure evolution of ASB:for the ASB within TA2, the calculation showed L=29.4 nm. It is very consistent with the TEM observations (i.e. the grain size was 30-70 nm in diameter).