镁合金板料数控热渐进成形时的摩擦和润滑性能

摘要

利用数控实验机床和摩擦实验研究AZ31镁合金板料数控热渐进成形时的摩擦和润滑机理.结果表明:镁合金薄板在加热条件下可以实现单点渐进成形；固体润滑膜可分为粘结型和吸附陶瓷型两种;固体石墨和MoS2润滑剂的初始摩擦因数均小于0.12,均可保证热渐进成形件获得良好的内外表面质量,没有任何划痕和裂纹等缺陷;吸附多孔陶瓷型固体润滑膜具有润滑和自润滑作用,固体润滑剂颗粒大小对初始摩擦因数有一定影响；固体BN粉末没有起到润滑作用,不能单独作为热渐进成形用固体润滑剂;当温度小于500℃时,固体石墨和MoS2粉末按一定比例配置的润滑复合喷剂的初始摩擦因数均小于为0.2,且表现出一定的协同作用.%The friction and lubrication mechanism of AZ31 magnesium alloy sheets in numerically controlled hot incremental forming were investigated by numerically controlled machine tools and friction tests. The results show that the single point incremental forming (SPIF) of magnesium alloy sheets can be achieved by heating. The solid lubricant film can be divided into two types, bonded and adsorbed ceramic coatings. The initial friction coefficients of graphite and M0S2 solid lubricant are both less than 0.12, which can ensure to obtain good inner and outer surface of hot incremental forming parts, without any defects such as scratches or cracks. The adsorbed porous ceramic solid lubricant film works as both lubrication and self-lubrication. The size of solid lubricant particles has an influence on the initial friction coefficient. The solid BN powder does not play the role of lubrication. As a result it can not be employed alone as a solid lubricant in hot incremental forming. When the temperature is lower than 500 'C, the initial friction coefficient of the composite sprays mixed with solid graphite and M0S2 powders by a certain proportion is less than 0.2, exhibiting a synergistic effect.