Brittle material fine particles with internal strain for use in aerosol deposition method

Abstract

A material composed of brittle material fine particles, such as ceramic or metalloid fine particles, for forming a composite structure on a substrate surface. The brittle material is pretreated to achieve a specific size range of fine particles and to develop a desired range of internal strain therein. The brittle material fine particles are adapted to form an aerosol with a gas stream, and when the aerosol is ejected to collide with a substrate surface, this causes collision of brittle material fine particles with a substrate surface thus imparting a mechanical impact to the fine particles. Such mechanical impact fractures or deforms the particles, and thereby generates an active new surface for brittle material fine particles after being fractured or deformed.

1 . Brittle material fine particles for forming a structure on a substrate surface, wherein the particles deform or fracture upon collision with a substrate or when a mechanical impact is imparted thereto, and the particles are provided with internal strain such that the particles generate an active new surface after being fractured or deformed.  
     
     
         2 . The brittle material fine particles according to  claim 1 , wherein the internal strain of the fine particles is 0.25%˜2.0%.  
     
     
         3 . The brittle material fine particles according to  claim 1 , wherein an average size of the fine particles is 0.1˜5 μm.  
     
     
         4 . The brittle material fine particles according to  claim 2 , wherein an average size of the fine particles is 0.1˜5 μm.  
     
     
         5 . The brittle material fine particles according to  claim 1 , wherein the fine particles are adapted to be incorporated into an aerosol so that the mechanical impact can be imparted thereto by blowing the aerosol against the substrate.  
     
     
         6 . The brittle material fine particles according to  claim 1 , wherein the internal strain is a lattice strain in the fine particles.  
     
     
         7 . The brittle material fine particles according  claim 1 , wherein the brittle material fine particles are provided with an increased said internal strain by processing the brittle material particles in at least one of a planetary grinder and a mill.  
     
     
         8 . The brittle material fine particles according to  claim 2 , wherein a value of the internal strain is calculated using Scherrer & Hall Method of an X-ray diffraction measurement.  
     
     
         9 . A brittle material for forming composite structure on a substrate surface, said material comprising: 
 a plurality of fine particles formed of the brittle material by pre-treating raw brittle material particles in at least one of a ball mill, a vibrating mill and a planetary grinder so as to increase an internal strain thereof while limiting formation of cracks therein.    
     
     
         10 . A material for forming composite structure according to  claim 9 , wherein the fine particles are adapted to be incorporated into an aerosol so that a mechanical impact can be imparted thereto by blowing the aerosol against the substrate; and the particles generate an active new surface upon collision with the substrate surface after fractured due to the mechanical impact.  
     
     
         11 . A material for forming composite structure according to  claim 9 , wherein the internal strain of the fine particles is 0.25%˜2.0%.  
     
     
         12 . A material for forming composite structure according to  claim 9 , wherein an average size of the fine particles is 0.1˜5 μm.  
     
     
         13 . A material for forming composite structure according to  claim 11 , wherein an average size of the fine particles is 0.1˜5 μm.