Flux-free soldering of aluminum-containing workpieces in a controlled atmosphere

In a furnace for flux-free soldering of aluminum-containing workpieces in a controlled atmosphere, a combination comprising wall means defining a furnace chamber through which workpieces to be soldered are to travel, said furnace chamber being constituted by a gas-tight thermally insulated metallic muffle and adapted to contain such workpieces in a controlled atmosphere, said muffle having an inlet and an outlet for the entry and exit of workpieces, respectively;

• a first lock chamber connected to said inlet, and a second lock chamber connected to said outlet;
• means connected to each lock chamber for creating a vacuum therein;
• admitting means for admitting a protective gas into said lock chambers and said muffle;
• first heating means for heating the interior of said first lock chamber;
• and second heating means for heating the protective gas atmosphere in said muffle.