合金 is read as ごうきん (goukin) and means alloy.
ごうきん
goukin
かゆうごうきん
fusible alloy
こくさいれんごうじどうききん
United Nations Children's Fund
きんぞくけつごう
metallic bond
あう
to be profitable
あわせる
to cause to meet (e.g. an unpleasant fate)
ごうりき
resultant force
がてん
consent
ごうどう
congruence
ごうい
(coming to an) agreement
ごうけい
sum total
ごうりか
rationalization
あいま
interval