铝和铝合金热挤压时润滑是很重要的。如果无润滑挤压,挤压制品较外的一层在热处理时就会出现粗晶粒,而且为去掉此一层表面往往须要进行大量的加工工作。无润滑挤压势必导至挤压力提高,这因为挤压毛料和挤压模之间发生摩擦之故。大家都已知道,油—石墨混合物作为润滑剂有这样的缺点:每挤压一次后又要重新涂上润滑剂,并且在挤压过程中不能确保均匀地润滑,因此易使制品表面出现缺陷。用粉状石墨作为润滑剂也作过试验,发现在挤压过程中会把它挤到挤压模表面高出来的 Lubrication of aluminum and aluminum alloys during hot extrusion is important. Without lubrication and extrusion, the outer layer of the extruded product will appear coarse grains during heat treatment, and a large amount of processing work is often required to remove the surface of this layer. No lubrication squeeze is bound to lead to increased extrusion pressure, which is due to squeeze wool and extrusion mold friction between the reason. It is known to all that oil-graphite compounds have the disadvantage of being lubricants, which are reprocessed after each squeeze, and which can not be uniformly lubricated during the squeeze, so that defects on the product surface can easily occur. Powdered graphite as a lubricant has also been tested and found that it will squeeze the extruded surface of the extrusion die high