Weldability & strength 1

[grippy]

Thanks in advance, group, for any help with this.

Q/1
I am finding conflicting opinion on the weldability of 7000 series aluminium alloys (in particular 7005). Older texts seem to say "not viable" and that it's "considered not structurally weldable in engineering circles". And yet empirical evidence belies that stance. Any thoughts, opinions, pointers much appreciated.

Q/2
I have it in the back of my mind that I once read that steel alloys have been produced which are claimed to actually be stronger after the welding process. Again, any comments from those more experienced than myself would be appreciated.

Jon Weaving

http://www.gripsport.com.au

 

[metengr]

Q/1
I am finding conflicting opinion on the weldability of 7000 series aluminum alloys (in particular 7005). Older texts seem to say "not viable" and that it's "considered not structurally weldable in engineering circles". And yet empirical evidence belies that stance. Any thoughts, opinions, pointers much appreciated.[/quote grippy]

Reply;
Below is web site concerning the weldability of various aluminum alloys that might be of interest;

http://www.alcotec.com/techpage.htm

Q/2
I have it in the back of my mind that I once read that steel alloys have been produced which are claimed to actually be stronger after the welding process. Again, any comments from those more experienced than myself would be appreciated. [/quote grippy]

Reply;
No, this is not really an accurate statement. The weld ican be made stronger using higher strength steel weld metal but the heat from welding will always introduce a local region of weakness adjacent to the weld region in the base metal being joined. Fortunately, steels can be heat treated after welding to eliminate this local region of weakness. However, heat treatment after welding is not always possible or feasible.