Abstract: A new process, slope transition and remelting used for spraying Al₂O₃ composite heat resistant layer on the surface of copper materials with oxyacetylene flam has been introduced. The microstructure of coating layer has been studied by using SEM. Particular attentions have been paid to diffusing reaction, liquid sintering, fine grains and other features. The effects of microstructural features on the bonding strength of coating layer, heat resistance, spalling resistance, etc have also been discussed. The Servia Life of the slag hole of blast furnace by using this Spraying technology and composition has increased by 2 times.