process for the production ultrahochvakuumdichter welded joint between aluminium and steel, especially stainless steel

摘要

This is an addn. to 2552199, which described welded joints withstanding ultra-high vacuum, between parts made of (a) steel, esp. austenitic stainless steels contg. Cr and/or Ni; and (b) Al; where part (a) is coated with an adhesive layer (c) contg. Ag. After applying layer (c) to part (a), the latter is heated 1 (2) hrs. at 100-961 degrees C. in inert gas at reduced press. to recrystallise layer (c). Parts (a,b) are then joined by friction welding. The pref. friction welding uses friction time of 0.1-20, (1-2) seconds with a press. of 2-50, (20) N/mm2, then upsetting time 2-8, (4-5) seconds with upsetting press. 20-100, (50-60) N/mm2. Part (b) is pref. the rotating part. The parent patent used argon arc welding to join parts (a,b), where a layer of Ni of Co was applied before the layer (c) of Ag. The present invention uses friction welding for making the joints.