An Nb—Ti—Co alloy having both good hydrogen permeability and {HEAD ~ good hydrogen embrittlement resistance} comprises one of {TAIL ~ Fe}, Cu or Mn as a fourth element, incorporating from 1 to 14 mol % 
An Nb — Ti — Co alloy having both good hydrogen permeability and { HEAD ~ good hydrogen embrittlement resistance } comprises one of { TAIL ~ Fe } , Cu or Mn as a fourth element , incorporating from 1 to 14 mol %
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH