In the paper, the propagation processes of two parallel cracks in 2-mm-thick plate pulled by the cyclic loading were investigated by numerical simulation and experiment. The codes Abaqus and Franc3D were implemented jointly to predict the crack growth path, the stress distribution around the cracks tip and the fatigue life. The corresponding fatigue experiment was carried out on a servo-hydraulic fatigue testing machine. The investigation indicates that the predicted crack paths agree well with the experimental results at the crack propagation early stage, and the predicted crack growth rate is consistent with the findings in experiment, which validate the prediction of the mixed mode crack propagation processes.

To conserve both energy and rare earths, a new technology for recycling of NdFeB magnet scrap was proposed in this paper based on the selective fluorination with AlF 3 -NaF melts. After fluorination, the reaction products were examined by scanning electron microscopy equipped with energy dispersive X-ray spectrometry, X-ray diffraction and inductively coupled plasma. Rare earth elements in the scrap were selectively converted to rare earth fluorides in the yield of ca. 94?2%, leaving Fe, B and impurities in the solid residue. The differences in chemical activity between Fe, impurities and rare earth should be mainly responsible for the selective fluorination process. The obtained fluorides can be subsequently processed with molten salt electrolysis for the direct production of Al-Nd based alloy.

Accurate control for Burning Through Point (BTP) can not only make the sintering process stable but also use the sintering area effectively. The condition of BTP affects the sintering output and quality. Currently there are no instruments that can be used to measure BTP online. In this paper, the online judgment of BTP is researched. The math model will be built based on the relation of measurable variables with BTP to judge the BTP online. Quadratic curve is fitted according to three measured points including the highest waste gas in five windboxes at discharge end. Leading correction for inertia measuring elements is also taken. Based on the math model derived, a feedback correction of BTP by bring in the temperature of waste gas in flue is needed duo to air leakage at discharge end to ensure the accurate of BTP judgment. In the paper an application of Soft measuring technique of BTP is introduced.Digital filter algorithm suitable to inertia and slow time-various characteristics of temperature is also introduced.