CO3W3C Fishbone-Like Hard Phase-Reinforced Fe-Based Wear-Resistant Coating and Preparation Thereof

Abstract

A Co 3 W 3 C fishbone-like hard phase-reinforced Fe-based wear-resistant coating and the preparation thereof, which belongs to the field of a wear-resistant coating on the surface of a material and a preparation method thereof. The wear-resistant coating comprises: 1.89-3.77% of C, 5.4-11.7% of Cr, 3.3-7.15% of Ni, 28.81-57.83% of W, 4.2-8.4% of Co, 0.03-0.065% of Si and the balance of Fe. The preparation process of the wear-resistant coating comprises: (1) before plasma cladding, pretreating a matrix; (2) pretreating an iron-based alloy powder; and (3) adjusting the process parameters of plasma cladding, preparing a cladding layer with a predetermined width and a predetermined thickness, and naturally cooling same down in air. The wear-resistant coating is simple in process; the prepared cladding layer has a strong metallurgical bonding property with the matrix structure, so that the best performance matching between the ceramic phase of the cladding layer and the matrix can be achieved; a fishbone-like hard phase Co 3 W 3 C has a very high hardness value and plays the role of a framework in the frictional process to reduce the wear of the matrix structure, thereby achieving an excellent wear resistance; plasma cladding is convenient to operate, and can be automatized; and the prepared wear-resistant layer is high in size precision and can be widely applied to surface modification of mechanical parts.

1 . A Co 3 W 3 C fish-bone-shape hard-phase reinforced Fe-based wear-resistant coating, characterized in that: the wear-resistant coating consists of the following alloy powder elements in weight percentage: C: 1.89-3.77%, Cr: 5.4-11.7%, Ni: 3.3-7.15%, W: 28.81-57.83%, Co: 4.2-8.4%, Si: 0.03-0.065%, and the remaining is Fe. 
     
     
         2 . A method for preparing the Co 3 W 3 C fish-bone-shape hard-phase reinforced Fe-based wear-resistant coating according to  claim 1 , characterized in that: a plasma cladding process is used to clad the Fe-based WC alloy powder on a surface of a metal matrix to form a wear-resistant high hardness coating with fish-bone-shape Co 3 W 3 C as the reinforcement phase; the specific steps are as follows:
 A pre-treatment of the matrix:
 polishing the surface of the matrix to remove oxide layer, placing the treated matrix on a plasma cladding working table, and adjusting its position; 
   B pre-treatment of the alloy powder:
 screening the WC powder with granularity of 280-320 meshes and the Fe-based alloy powder of 100-200 meshes, preparing the Fe-based WC mixed alloy powder of the mentioned weight percentage, putting in a stirrer to stir for 50-60 min, putting in a drying oven to heat at 150° C., and putting in a plasma cladding machine after finishing the above pre-treatments; 
   C plasma cladding:
 the plasma cladding process includes the following technical parameters: a working current of 135-145 A, a working voltage of 11-12 V, powder feeding gas and protecting gas are argon gas, a powder feeding gas pressure of 280-300 MPa, a protecting gas pressure of 700-800 MPa, distance from a nozzle to the surface of the matrix is 10 mm, and a scanning speed of 80 mm/min; and 
   D treatment of a cladding layer:
 after finishing the plasma cladding process, turning off the plasma cladding machine, cutting the side and the front of the cladding layer, grinding and polishing, and fish-bone-shape hard phase is observed under an optical microscope and an electron microscope; in conjunction with the X ray diffraction analysis result, the hard phase is identified as Co 3 W 3 C, which exhibits high performance in a hardness test and a wear resistance test.