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