Manufacturing method of high entropy alloy coating layer

Abstract

A manufacturing method of a high entropy alloy (HEA) coating is provided. The manufacturing method of the HEA coating includes: melting a HEA material, wherein the HEA material comprises at least four metal elements, and the at least four elements are contained in the HEA material with substantially the same content; performing a gas atomization process on the molten HEA material to form HEA powders; and performing a plasma spray process to heat the HEA powders, and spray the heated HEA powders onto a target substrate.

1 . A manufacturing method of a high entropy alloy (HEA) coating layer, comprising:
 melting a HEA material, wherein the HEA material comprises at least four metal elements, and the at least four elements are contained in the HEA material with substantially the same content;   performing a gas atomization process on the molten HEA material to form HEA powders; and   performing a plasma spray process to heat the HEA powders, and spray the heated HEA powders onto a target substrate.   
     
     
         2 . The manufacturing method of the HEA coating layer of  claim 1 , wherein the molten HEA material is rapidly cooled down from a high temperature to a low temperature during the gas atomization process, the high temperature ranges from 1150° C. to 1500° C., and the low temperature ranges from 100° C. to 250° C. 
     
     
         3 . The manufacturing method of the HEA coating layer of  claim 1 , wherein the HEA powders homogeneously consist of a low temperature crystalline phase. 
     
     
         4 . The manufacturing method of the HEA coating layer of  claim 3 , wherein the low temperature crystalline phase is a body-centered cubic (BCC) phase. 
     
     
         5 . The manufacturing method of the HEA coating layer of  claim 1 , wherein the HEA powders consist of a low temperature crystalline phase and a high temperature crystalline phase, and a content of the a high temperature crystalline phase in the HEA powders is greater than 0%, and less than 10%. 
     
     
         6 . The manufacturing method of the HEA coating layer of  claim 1 , wherein shapes of the HEA powders are substantially spherical, and an average diameter of the HEA powders ranges from 60 μm to 90 μm. 
     
     
         7 . The manufacturing method of the HEA coating layer of  claim 1 , wherein a working gas of the plasma spray process comprises an Ar gas and a H 2  gas, and a ratio of a flow rate of the Ar gas with respect to a flow rate of the H 2  gas ranges from 1.5:1 to 34:1. 
     
     
         8 . The manufacturing method of the HEA coating layer of  claim 1 , wherein a power of the plasma spray process ranges from 20 kW to 55.5 kW. 
     
     
         9 . A HEA coating layer, formed by the manufacturing method of the HEA coating layer of  claim 1 , wherein a content of a high temperature crystalline phase in the HEA coating layer is less than 10%, and greater than or equal to 0%. 
     
     
         10 . The HEA coating layer of  claim 9 , wherein a hardness of the HEA coating layer ranges from 230 HV to 600 HV, and the HEA coating layer is ferromagnetic. 
     
     
         11 . The HEA coating layer of  claim 9 , wherein the high temperature crystalline phase is a face-centered cubic (FCC) phase. 
     
     
         12 . The HEA coating layer of  claim 9 , wherein the HEA coating layer is substantially free of the high temperature crystalline phase. 
     
     
         13 . The HEA coating layer of  claim 9 , wherein the HEA coating layer homogeneously consists of a low temperature crystalline phase. 
     
     
         14 . The HEA coating layer of  claim 13 , wherein the low temperature crystalline phase is a body-centered cubic (BCC) phase.