A wear and tear resistant surface coating for a breaking hammer piston base

Abstract

The application provides a wear-resistant and pull-resistant breaking hammer piston base surface coating and belongs to the technical field of breaking hammer piston surface coating. It solves the problem that the outer circle of the existing breaking hammer piston is only quenched and tempered, the base material is directly exposed, is easily pulled under the working condition of impurity-containing hydraulic oil and eccentric impact, and after being pulled, the sealing is invalid and oil leaks, which leads to the decline of the impact force of the breaking hammer, low efficiency and even unable to work. The wear-resistant and pull-resistant breaking hammer piston base surface coating is characterized in that the piston base surface comprises a protective coating composed of a Cr transition layer, a Cr and WC composite coating, a WC and C composite coating and a DLC coating. The application has the advantages of not needing to use other ion source ionized acetylene, reducing the process steps of the existing coating film, controllable process, high product stability and avoiding product pull and oil leakage.

Description

Technical Field

[0001] This invention belongs to the technical field of surface coating for hydraulic breaker pistons, and relates to a wear-resistant and tensile-resistant surface coating for the substrate of a hydraulic breaker piston. Background Technology

[0002] Hydraulic breakers are used in high-frequency impact operations in mining and earthmoving projects. The piston reciprocates at high frequency inside the cylinder. The clearance between the piston and the cylinder is narrow, and hydraulic oil sealing is achieved by the outer edge sealing ring.

[0003] The on-site working conditions are harsh. Sand and gravel dust and metal shavings can easily penetrate the hydraulic oil and form hard abrasive particles. When the crushing force is unevenly loaded, the piston will rub against the cylinder eccentrically. Many existing hydraulic breakers only have the outer diameter of the piston treated with heat treatment, leaving the base material directly exposed. Under the condition of hydraulic oil containing impurities and eccentric impact, the base material is easily scratched. After scratching, the seal fails and oil leaks, resulting in a decrease in the impact force of the hydraulic breaker, low efficiency, or even failure to work. Summary of the Invention

[0004] The purpose of this invention is to address the aforementioned problems in the prior art by providing a wear-resistant and tear-resistant coating for the piston substrate surface of a hydraulic breaker that prevents scratching of the bare piston substrate.

[0005] The objective of this invention can be achieved through the following technical solution: a wear-resistant and tensile-resistant hydraulic breaker piston substrate surface coating, characterized in that the piston substrate surface includes a protective coating composed of a Cr transition layer, a Cr and WC composite coating, a WC and C composite coating, and a DLC coating.

[0006] In the above-mentioned wear-resistant and tensile-resistant hydraulic breaker piston substrate surface coating, the thickness of the protective coating is ≥3μm.

[0007] In the above-mentioned wear-resistant and tensile-resistant hydraulic breaker piston substrate surface coating, the Cr transition layer, Cr and WC composite coating, and WC and C composite coating are obtained by DC magnetron sputtering, and the DLC coating is obtained by ionizing acetylene gas by self-biased glow discharge under closed magnetic field control.

[0008] In the aforementioned wear-resistant and tensile-resistant hydraulic breaker piston substrate surface coating, the Cr transition layer is applied using DC magnetron sputtering.

[0009] In the aforementioned wear-resistant and tensile-resistant hydraulic breaker piston substrate surface coating, a negative voltage is applied to the piston substrate to ionize acetylene for DLC coating deposition.

[0010] Compared with existing technologies, this wear-resistant and scratch-resistant breaker piston substrate surface coating has the advantages of eliminating the need for ionizing acetylene with other ion sources, reducing the process steps of existing coating films, having controllable processes, high product stability, and avoiding product scratches and oil leakage. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the surface coating of the piston substrate of the wear-resistant and tensile-damage-resistant hydraulic breaker.

[0012] In the figure, 1 is the piston substrate; 2 is the Cr transition layer; 3 is the Cr and WC composite coating; 4 is the WC and C composite coating; 5 is the DLC coating; and 6 is the protective coating. Detailed Implementation

[0013] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0014] like Figure 1 As shown, the wear-resistant and tensile-resistant hydraulic breaker piston substrate surface coating includes a protective coating 6 composed of a Cr transition layer 2, a Cr and WC composite coating 3, a WC and C composite coating 4, and a DLC coating 5.

[0015] To elaborate further, the total thickness of the protective coating 6 is ≥3μm.

[0016] Preferably, the Cr transition layer 2, the Cr and WC composite coating 3, and the WC and C composite coating 4 are obtained by DC magnetron sputtering, and the DLC coating 5 is obtained by ionizing acetylene gas by self-biased glow discharge under closed magnetic field control.

[0017] The pretreated piston substrate 1 is placed in the vacuum chamber of the sealed container of the coating equipment. Argon gas is introduced into the vacuum chamber, and the pressure of the introduced argon gas is controlled between 5×10-1 Pa and 10×10-1 Pa. The ion source power is controlled at 1100 W and the voltage is less than 100 V.

[0018] To elaborate further, the Cr transition layer 2 is deposited by DC magnetron sputtering, followed by the deposition of a WC / C coating, which results in fast deposition, uniform and dense film, and stable process.

[0019] Preferably, a negative voltage is applied to the piston substrate 1 to ionize acetylene for DLC coating 5 deposition.

[0020] Acetylene at 700 sccm is introduced into the vacuum chamber and its vacuum level is maintained at 6×10-1 Pa to 10×10-1 Pa. A negative bias voltage of -400V to -700V is applied to the product. No additional ion source is used, and the deposition time of a single-layer DLC coating is between 60 and 180 minutes.

[0021] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

[0022] Although this document frequently uses terms such as piston substrate 1, Cr transition layer 2, Cr and WC composite coating 3, WC and C composite coating 4, DLC coating 5, and protective coating 6, the possibility of using other terms is not excluded. These terms are used merely for the convenience of describing and explaining the essence of the invention; interpreting them as any additional limitation would contradict the spirit of the invention.

Claims

1. A wear-resistant and tensile-damage-resistant coating for the piston substrate surface of a hydraulic breaker, characterized in that, The piston substrate (1) has a protective coating (6) consisting of a Cr transition layer (2), a Cr and WC composite coating (3), a WC and C composite coating (4), and a DLC coating (5).

2. The wear-resistant and tear-resistant surface coating of the hydraulic breaker piston substrate (1) according to claim 1, characterized in that, The thickness of the protective coating (6) is ≥3μm.

3. The wear-resistant and tensile-damage-resistant coating for the piston substrate surface of a hydraulic breaker according to claim 1, characterized in that, The Cr transition layer (2), Cr and WC composite coating (3), and WC and C composite coating (4) are obtained by DC magnetron sputtering, and the DLC coating (5) is obtained by ionizing acetylene gas by self-biased glow discharge under closed magnetic field control.

4. The wear-resistant and tensile-resistant coating for the piston substrate surface of a hydraulic breaker according to claim 1, characterized in that, The Cr transition layer (2) was sputtered by DC magnetron sputtering.

5. The wear-resistant and tensile-resistant coating for the piston substrate surface of a hydraulic breaker according to claim 1, characterized in that, A negative voltage is applied to the piston substrate (1) to ionize acetylene for DLC coating (5) deposition.

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