Research On In-situ Synthesized TiB₂/Al Matrix Composites By Airflow Way

There is a very well foreground in fabricating TiB₂/Al composite by in-situ, but it's property is restricted for TiB₂ reuniting easily.So that, based on the traditional way, the paper used Al-Ti-KBF₄ as the reatant and introdued the new technique of airflow combining with flash-mill, fabricated the TiB2/Al composite in which the grain of TiB2 was thin and dispersive.Then the paper analysed the reactive energeticsy procession of Al-Ti-KBF4 by XRD SEM EDS way, except that it also researched what is the effect of different processing parameter and the active elements Mg RE to the size and distribution of TiB₂ in the composite, and obtained the best technique.At last, the paper reseached the properity of TiB₂/Al-4.5Cu and TiB_@-TiC/Al-4.5Cu composites fabricated by airflow way. The study shows that:(1) It can restrain some slag by controlling the atomic propotion of Ti and B as 1: 2 in the reaction system of Al-Ti-KBF4, and will obtain pure TiB2 reinforce in the metal meltment.(2) Uder some range of the TiB₂ percent , the airflow way can restrain the TiB₂ to reunite in the boundary of crystal, and get more thin and desperse TiB₂ than the traditional way of adding to massive salt-mixture, the grain of TiB₂ fabricated by this way is sprawn or polygon and is about 0.5um.But if the percent of TiB2 is more than 10% , the airflow way is also diffuct to restrain the TiB₂ reuniting.(3) The processing parameter such as the reaction temperation , mixing speed and so on, shows great influence on the distribution and the size of TiB2 in the composite during the fabricating by airflow way .The paper obtained the best proper temperation is about 850℃ , mixing speed is 600-800 turns/min.(4) Compared with the way of adding to massive salt-mixture , the 5%TiB2/Al-4.5Cu composite's mechanical properties fabricated by airflow way all have increased , such as the tensile strength moved up 37.3% and the elongation...