CN104388876A

CN104388876A - WC-HfO2 nano coating and preparation method thereof

Info

Publication number: CN104388876A
Application number: CN201410603926.XA
Authority: CN
Inventors: 程敬卿
Original assignee: Anhui Ding Heng Manufacturing Technology Research Institute Co Ltd
Current assignee: Anhui Ding Heng Manufacturing Technology Research Institute Co Ltd
Priority date: 2014-10-30
Filing date: 2014-10-30
Publication date: 2015-03-04
Anticipated expiration: 2034-10-30

Abstract

The invention relates to a WC-HfO2 nano coating and a preparation method thereof. The WC-HfO2 nano coating comprises the following components in percentage by mass: 19.31%-37.47% of WC, 61.26%-79.42% of HfO2 and 1.27% of microelements, wherein the microelements comprise Ni, Cr, Si, B and Mo. The preparation method of the WC-HfO2 nano coating comprises the following steps: firstly preparing nanospheres of WC and HfO2 by a dry crushing method, then mixing Ni, Cr, Si, B and Mo by an activator protection method to prepare nanopowder, and subsequently preparing the WC-HfO2 nano coating on a 9Cr18 die steel substrate by a plasma spraying process. The WC-HfO2 nano coating is relatively high in content of HfO2, so that the coating is relatively high in adhesive strength and adhesion force, superior to the conventional coating material, high in hardness and high in abrasion resistance; the problems of low abrasion resistance and low corrosion resistance of the existing coating are solved; the fine texture and structure of the material surface coating are improved.

Description

A kind of WC-HfO 2nano coating and preparation method thereof

Technical field

The present invention relates to technical field of hot, is a kind of WC-HfO specifically ₂nano coating and preparation method thereof.

Background technology

Plasma spraying technology is the accurate spraying method of a kind of new multi-purpose greatly developed after flame plating, and it has: 1, ultrahigh-temperature characteristic, is convenient to the spraying carrying out materials with high melting point; 2, the speed of jet particle is high, and coating is fine and close, and cohesive strength is high; 3, owing to using rare gas element as working gas, so spray material is not oxidizable.

Along with popularizing of plasma spraying technology, increasing workpiece brings into use plasma spraying recovery technique " to come back to life ", but the material kind of workpiece is different, working conditions is different, and the spraying method adopted during reparation and spray material are also different.

The problem poor for existing coating ubiquity wear resistance, erosion resistance is lower, people need one to coordinate re-manufacturing technology, for improving microtexture, the structure of material surface coating, improve the type material of coating hardness.

Summary of the invention

For above-mentioned technical problem, the invention provides a kind of WC-HfO ₂nano coating and preparation method thereof.

Technical problem to be solved by this invention realizes by the following technical solutions:

A kind of WC-HfO ₂nano coating, the mass percent of its component and each component is that WC accounts for 19.31%-37.47%, HfO ₂account for 61.26%-79.42%, trace element accounts for 1.27%, described trace element comprises Ni, Cr, Si, B, Mo, and WC is only second to adamantine second hard material, there is good physics, chemical property, Young's modulus and diamond close, thermostability is higher than diamond, HfO ₂can improve intensity and the toughness nearly 50% of material, some rare earth elements added can improve conjugation, the grasping force of coating.

A kind of WC-HfO ₂the preparation method of nano coating, comprises the following steps: first adopt promoting agent protection method to obtain WC and HfO ₂nanometer ball, then adopt promoting agent protection method mix Ni, Cr, Si, B, Mo obtain nanometer powder, afterwards adopt plasma spray coating process on 9Cr18 die steel matrix, prepare WC-HfO ₂nano coating.

The invention has the beneficial effects as follows: HfO of the present invention ₂content is higher, so anchoring strength of coating, grasping force is higher, be better than conventional washcoat material, hardness is high, wear resistance is good, solve existing coating abrasion performance poor, the problem that erosion resistance is lower, improve the microtexture of material surface coating, structure, coating hardness is made to improve 50%, Young's modulus improves 8.5%-14.4%, thus entirety improves the wear resisting property of material surface, also there is significant effect to the comprehensive mechanical property improving improvement simultaneously, be applicable to plasma spraying, available spraying steel have: 2Cr13, 4Cr13, 9Cr18, 4Cr5W2VSi, 8Cr3 etc.

Embodiment

The technique means realized to make the present invention and creation characteristic are easy to understand, and set forth further below to the present invention.

Embodiment one:

A kind of WC-HfO ₂nano coating, the mass percent of its component and each component is that WC accounts for 19.31%, HfO ₂account for 79.42%, trace element accounts for 1.27%, described trace element comprises Ni, Cr, Si, B, Mo.

Described WC-HfO ₂the workpiece of nano coating and the performance comparison experimental result of 20Cr round steel matrix are in table 1.

Described WC-HfO ₂the friction and wear behavior experimental result of the workpiece of nano coating and the friction and wear behavior experimental result of 20Cr round steel matrix contrast in table 2.

Embodiment two:

A kind of WC-HfO ₂nano coating, the mass percent of its component and each component is that WC accounts for 37.47%, HfO ₂account for 61.26%, trace element accounts for 1.27%, described trace element comprises Ni, Cr, Si, B, Mo.

A kind of WC-HfO ₂the preparation method of nano coating, with embodiment one.

Embodiment three:

A kind of WC-HfO ₂nano coating, the mass percent of its component and each component is that WC accounts for 28.53%, HfO ₂account for 70.2%, trace element accounts for 1.27%, described trace element comprises Ni, Cr, Si, B, Mo.

Described nano coating can adopt plasma spray coating process to prepare WC-HfO2 nano coating on 9Cr18 die steel matrix.

Test the bonding strength of coating, microhardness, void content and abrasive wear resistance, and utilize XRD to carry out Phase Structure Analysis to dusty spray Ji coating, by scanning electronic microscope, the coating morphology before and after dusty spray, abrasive wear is observed, main experimental results and conclusion as follows:

The workpiece of table 1 WC-HfO2 nano coating and the performance comparison experimental result of 20Cr round steel matrix:

Can be obtained by experimental data, WC-HfO ₂nano coating effectively can reduce the porosity of workpiece surface, improves the bonding strength of workpiece surface, can significantly improve the microhardness of workpiece surface.

WC-HfO in each embodiment of table 2 ₂the friction and wear behavior experimental result of nano coating:

Group	Before test (g)	After test (g)	Loss (mg)
				Embodiment one	49.6246	49.6237	0.9
Embodiment two	49.8356	49.8346	1.0
				Embodiment three	49.8545	49.8533	1.2
Control group	49.4578	49.4456	12.2

From table 2, WC-HfO ₂nano coating has excellent wear resistance.

Result shows: described WC-HfO ₂the relative density of nano coating can reach 95.4%, does not have obvious gap, WC-HfO between disperse cubic boron nitride particle and ultra-fine cemented carbide matrix ₂the bending strength of nano coating is 823MPa, and hardness ranges up to HRC68, and density can reach 3.13g/cm ³, coating thickness can reach 5 millimeters, and density is well 0.82, and at identical conditions, the abrasion loss of 12CrNi3A is WC-HfO ₂10 times of coating, this shows WC-HfO prepared by plasma ₂coating has excellent abrasive wear resistance.

More than show and describe ultimate principle of the present invention, principal character and advantage of the present invention.The technician of the industry should understand; the present invention is not restricted to the described embodiments; the just principle of the present invention described in above-described embodiment and specification sheets; without departing from the spirit and scope of the present invention; the present invention also has various changes and modifications, and these changes and improvements all fall in the claimed scope of the invention.Application claims protection domain is defined by appending claims and equivalent thereof.

Claims

1. a WC-HfO ₂nano coating, is characterized in that: the mass percent of its component and each component is that WC accounts for 19.31%-37.47%, HfO ₂account for 61.26%-79.42%, trace element accounts for 1.27%, described trace element comprises Ni, Cr, Si, B, Mo.

2. a WC-HfO ₂the preparation method of nano coating, is characterized in that: comprise the following steps: first adopt promoting agent protection method to obtain WC and HfO ₂nanometer ball, then adopt promoting agent protection method mix Ni, Cr, Si, B, Mo obtain nanometer powder, afterwards adopt plasma spray coating process on die steel matrix, prepare WC-HfO ₂nano coating.