Integrated polymer-derived ceramic thin-film sensor produced by laser pyrolysis and additive manufacturing and fabrication method thereof

Abstract

An integrated polymer-derived ceramic (PDC) thin-film sensor produced by laser pyrolysis and additive manufacturing and a fabrication method thereof are provided. Using a metal component or an insulating material as a substrate, a PDC-doped composite insulating film layer with high density, high insulation, and high temperature resistance is formed by a layer-by-layer laser pyrolysis and additive manufacturing on the surface of the metal component, and a strain sensitive layer with excellent electrical conductivity is obtained by Weissenberg direct writing process PDC-doped filler sensitive grid on the composite insulating film layer and laser pyrolysis enhancing graphitization of PDC. In this way, the in situ integrated laser fabrication of highly insulating film layer, sensitive grid with excellent electrical conductivity, and metal substrate based on PDC materials is developed, which achieves the laser processing of liquid-solid-function transformation of PDC composites and allows the successful use thereof in strain sensing of metallic materials.

Claims

1. An integrated polymer-derived ceramic (PDC) thin-film sensor produced by laser pyrolysis and additive manufacturing, wherein the sensor comprises a base and a sensitive grid, the sensitive grid is in situ fabricated on the base through the laser pyrolysis, and the sensitive grid is composed of a PDC-doped conductive filler; a thickness of the sensitive grid ranges between 10-20 m; wherein a fabrication method of the sensor comprises the following steps: preparing a mixed solution of a conductive filler and a PDC solution, and writing the mixed solution directly on the base through a Weissenberg direct writing process, after heating and solidifying, performing a laser treatment at the same temperature to obtain the integrated PDC thin-film sensor.

2. The integrated PDC thin-film sensor produced by laser pyrolysis and additive manufacturing according to claim 1, wherein the base of the integrated PDC thin-film sensor is composed of a substrate, a transition layer, and a composite insulating layer arranged in sequence.

3. The integrated PDC thin-film sensor produced by laser pyrolysis and additive manufacturing according to claim 1, wherein the base is an insulating alumina substrate.

4. The integrated PDC thin-film sensor produced by laser pyrolysis and additive manufacturing according to claim 2, wherein the sensor successively comprises, from bottom to top, the substrate, the transition layer, the composite insulating layer, and the sensitive grid, a thickness of the composite insulating layer ranges between 50 m-200 m, and the substrate is made of a metallic material.

5. The integrated PDC thin-film sensor produced by laser pyrolysis and additive manufacturing according to claim 4, wherein the composite insulating layer and the sensitive grid of the sensor are both based on a PDC material, the composite insulating layer is composed of a PDC-doped inert insulating filler.

6. The integrated PDC thin-film sensor produced by laser pyrolysis and additive manufacturing according to claim 5, wherein the substrate is made of a Ni-based alloy material, and the composite insulating layer comprises an insulating layer and an infiltration insulating layer; the insulating layer comprises a first sub-insulating layer and a second sub-insulating layer, the infiltration insulating layer comprises a first sub-infiltration insulating layer and a second sub-infiltration insulating layer, a fabrication method of the base of the sensor comprises the following steps: subjecting a nickel-based alloy sheet to successive ultrasonic cleaning and drying, and then depositing a transition layer on the nickel-based alloy sheet by a magnetron sputtering machine; preparing a mixed solution of the PDC solution and inert insulating powder, and writing the mixed solution directly on the transition layer in step 1) through the Weissenberg direct writing process, after heating and solidifying, performing the laser treatment at the same temperature to form the first sub-insulating layer, after cooling to room temperature, coating a layer of the mixed solution on the insulating layer by screen printing, and then conducting heating, solidifying, and the laser treatment to form the second sub-insulating layer; preparation of the infiltration insulating layer: preparing a mixed solution of inert insulating powder with infiltration effect and the PDC solution, coating the mixed solution on the second sub-insulating layer by screen printing, after heating and solidifying, conducting the laser heat treatment to obtain the first sub-infiltration insulating layer, preparing the second sub-infiltration insulating layer in the same way.

7. The integrated PDC thin-film sensor produced by laser pyrolysis and additive manufacturing according to claim 6, wherein a thickness of the transition layer ranges between 3-10 m.

8. The integrated PDC thin-film sensor produced by laser pyrolysis and additive manufacturing according to claim 1, wherein before the step of writing the mixed solution directly on the base through a Weissenberg direct writing process, the base is subject to successive ultrasonic cleaning and drying.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic diagram showing the fabrication process of the integrated PDC thin-film strain sensor produced by laser pyrolysis and additive manufacturing in Embodiment 1.

(2) FIG. 2 is a schematic diagram showing the fabrication process of the integrated PDC thin-film strain sensor produced by laser pyrolysis and additive manufacturing in Embodiment 2.

(3) FIG. 3 is a schematic diagram showing the film layer structure of the composite insulating layer in Embodiment 2.

(4) FIG. 4 is a structural diagram of the integrated thin-film strain sensor in Embodiment 2.

(5) FIG. 5 is an atomic force microscope (AFM) image of the sensitive grid after laser treatment.

(6) FIG. 6 is a strain signal test diagram of the integrated thin-film strain sensor in Embodiment 2.

(7) In the drawings: 1 represents a nickel-based alloy substrate, 2 represents a PDC composite insulating film layer, 3 represents a PDC sensitive grid, and 4 represents a sensitive grid electrode.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(8) In order to make the purposes, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Embodiment 1

(9) The present embodiment provides a PDC strain sensor with an insulating substrate produced by laser pyrolysis and additive manufacturing, which sequentially includes, from bottom to top, the insulating substrate and a strain sensitive grid. The thickness of the sensitive grid ranges between 10-20 m.

(10) The specific fabrication process of the above-mentioned laser-cladding PDC strain sensor with the insulating substrate is shown in FIG. 1 and specifically includes the following steps:

(11) 1) Pre-treatment: First, the alumina substrate 5 is ultrasonically cleaned for 20-60 min, dried in a drying oven, and removed.

(12) 2) Preparation of the sensitive grid 3: A mixed solution of conductive powder and PDC is prepared and written directly on the insulating substrate (i.e. the alumina substrate 5) in step 1) using the Weissenberg direct writing process. After solidifying for 20 min, a laser treatment is performed, such that the graphitization transformation of organic matters is achieved and enhanced by laser pyrolysis. AFM shows the generation of graphite, as shown in FIG. 5.

(13) Thus, the PDC strain sensor with the insulating substrate is fabricated.

Embodiment 2

(14) The present embodiment provides an integrated PDC thin-film strain sensor produced by laser pyrolysis and additive manufacturing, which sequentially includes, from bottom to top, a nickel-based alloy substrate, a composite insulating layer, and a strain sensitive grid. The thickness of the composite insulating layer ranges between 50-200 m. The thickness of the sensitive grid ranges between 10-20 m.

(15) The specific fabrication process of the above-mentioned integrated PDC strain sensor is shown in FIG. 2 and specifically as follows:

(16) 1) Pre-treatment: A nickel-based alloy sheet 1 is ultrasonically cleaned for 20-60 min and dried in a drying oven. A transition layer of 3-10 m is deposited by sputtering on the nickel-based alloy sheet 1 through a magnetron sputtering machine.

(17) 2) Preparation of the insulating layer: A mixed solution of PDC solution, insulating powder, and insulating powder with infiltration effect is prepared, stirred with a magnetic stirrer for 1 h, and taken out for use. The thickness of the insulating layer is accurately controlled by the Weissenberg direct writing process. After solidifying for 20-60 min, a laser treatment is performed. After naturally cooling to room temperature, a second layer of the same mixed solution is coated on the insulating layer using screen printing technique, followed by similar solidifying, cross-linking, and laser treatment with identical laser parameters.

(18) 3) Preparation of the infiltration insulating layer: A mixed solution of infiltration insulating powder and PDC solution, magnetically stirred for 1-2 h, and taken out. The mixed solution is coated on the insulating layer obtained in step 2) similarly by screen printing. After solidification, a laser scanning heat treatment is conducted to yield a relatively dense infiltration layer. A second infiltration insulating layer is prepared with the same method and parameters, and finally, a composite insulating film layer 2 as shown in FIG. 3 is obtained.

(19) 4) Preparation of the sensitive grid 3: A mixed solution of conductive powder and PDC is prepared and written directly on the composite insulating layer prepared in steps 2) and 3) using the Weissenberg direct writing process. After solidifying for 20 min, a laser treatment is performed, such that the graphitization transformation of organic matters is enhanced by laser pyrolysis. AFM shows the generation of graphite, as shown in FIG. 5.

(20) 5) Manufacturing of solder joints and lead wires of thin-film strain sensor: Platinum wires are adhered to two solder joints of the sensitive grid with commercial graphene conductive glue, followed by standing for 5-12 h and heating at 120-150 C. for 2 h to realize a relatively firm contact between the lead wires and the solder joints.

(21) Thus, the integrated PDC thin-film strain sensor is fabricated, as shown in FIG. 4.

(22) The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: the technical solutions described in the foregoing embodiments can be modified, or some of the technical features can be equivalently replaced. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.