Powder material for sintering and solid latent heat storage member including the same

A solid latent heat storage member comprising a bulk body obtained by pressurized sintering a powder material in a vacuum atmosphere so that powder particles of the powder material are directly bonded each other to form the bulk body,

• the powder material comprising vanadium and oxygen as main components, wherein the powder material comprises a VO2-based vanadium oxide and one or more types of vanadium oxides other than the VO2-based vanadium oxide, the VO2-based vanadium oxide containing an oxide obtained by partial substitution of V of an oxide represented by a chemical formula VO2 with one or more substitution elements of W, Cr and Al, and having a proportion of the partial substitution of more than 0 atomic % and 20 atomic % or less, wherein, when ratio of sum of atomic % of the vanadium and the substitution elements to atomic % of the oxygen in all powder is expressed as 1:(2+d), d is 0<d<0.1,
• a surface of the powder has been oxidized by heating in an air atmosphere so that the surface of the powder comprises a V2O5-based vanadium oxide,
• a latent heat quantity per volume of the solid latent heat storage member is 100 J/cc or more,
• the bulk body has a foam-like pattern structure, which is observed by a scanning electron microscope, inside,
• a relative density of the bulk body based on the density of VO2 is 90% or more, and
• a compression strength of the bulk body is 46 MPa or higher.