link up vs weld together

link up

verb
  • To become linked or joined together. 

  • To link or join together. 

  • To meet with someone. 

weld together

verb
  • To forge a social or emotional bond between people. 

  • Used other than figuratively or idiomatically: see weld, together. 

How often have the words link up and weld together occurred in a corpus of books? (source: Google Ngram Viewer )