NOVELTY - The improved slurry spray process comprises adding yttria-stabilized zirconia (YSZ) powder in a non aqueous solvent to obtain YSZ slurry having a solid loading of 2-4 vol.%, preparing a surface of strontium doped lanthanum manganite (LSM) substrate using silicon carbide abrasive papers having a grit size of 180-1000, fixing LSM substrate on a mandrel, rotating the mandrel at a speed of 120-2000 revolutions per minute with preheating the rotating LSM substrate for 3-5 minutes at a temperature of 40-50 degrees C, and spraying the slurry with carrier gas onto the rotating LSM substrate.    USE - The improved slurry spray process is useful for coating a YSZ on a LSM substrate such as a dense and crack free YSZ coated LSM tube, which is useful for solid oxide fuel cell applications (all claimed).    ADVANTAGE - The improved slurry spray process is capable of economically, rapidly and simply providing the crack-free and dense YSZ coating on the LSM substrate with high uniformity and without requiring highly specialized equipments and operators and several coating and sintering cycles thus enhancing efficiency of the fuel cell.    DETAILED DESCRIPTION - The improved slurry spray process comprises adding yttria-stabilized zirconia (YSZ) powder in a non aqueous solvent to obtain YSZ slurry having a solid loading of 2-4 vol.%, preparing a surface of strontium doped lanthanum manganite (LSM) substrate using silicon carbide abrasive papers having a grit size of 180-1000, fixing LSM substrate on a mandrel, rotating the mandrel at a speed of 120-2000 revolutions per minute with preheating the rotating LSM substrate for 3-5 minutes at a temperature of 40-50 degrees C, spraying the slurry with carrier gas onto the rotating LSM substrate for a period of 3-5 minutes at a temperature of 40-50 degrees C, drying YSZ coated LSM substrate at a temperature of 40-50 degrees C for a period of 12-16 hours, and sintering YSZ coated LSM substrate at a temperature of 1410-1460 degrees C for a period of 5-6 hours to obtain a dense and crack free YSZ coated LSM tube for silicon oxide fuel cell application. The YSZ slurry is prepared without addition of any dispersant, binder or plasticizer. The temperature of LSM substrate is maintained by a commercial hand dryer for better adherence and rapid drying of YSZ film. A thickness of YSZ coating on LSM substrate is 15-23 mu m. A scanning electron microscopy analysis of a cross-section of the coated LSM substrate shows that the coating is dense and uniform.    DESCRIPTION OF DRAWING(S) - The diagram shows a scanning electron microscope analysis of a cross-section of an YSZ coated LSM tube.