Abstract: A metal material having a photocatalytic activity which comprises an anodized layer and a thin layer containing titanium oxide powder which are heat treated are sequentially laminated on the surface of a substrate comprising metal material including titanium. By anodically oxidizing the metal material including titanium, an anodized layer is formed on the surface thereof. A thin layer containing titanium oxide powder is further coated on this surface, and heat treatment is carried out before and/or after forming this thin layer containing titanium oxide powder.

Abstract: There is provided a Ti-Mo alloy containing 0.2 to 3.0 wt % of molybdenum, with the balance being substantially titanium, characterized in that the amount of Fe in the impurities is not greater than 0.1% and the amount of O.sub.2 in the impurities is in the range that satisfies the following equation on the basis of the amount of Mo (%).O.sub.2 (%).ltoreq.9/35-1/28.multidot.Mo (%)said titanium alloy being highly resistant to pitting corrosion in an environment where there are bromide ions and being superior in formability. Said alloy undergoes heating at a temperature higher than 700.degree. C. and lower than the .alpha.-transformation point and then cooling at a rate of 500.degree. C./min or less, whereby said alloy is rendered malleable.

Abstract: A sacrificial anode for use in preventing corrosion of copper alloy parts and hydrogen absorption in titanium or titanium alloy parts of an apparatus useful for treating hot sea water, comprising a metal or metal alloy which maintains the potential of said copper alloy parts and titanium or titanium alloy parts serving as cathodes in said apparatus in the range of -0.5 to -0.65 V, relative to the potential of a saturated calomel electrode.