CZ304082B6 - Device to determine adherence of applied coating when loading thereof by tension - Google Patents

Abstract

In the present invention, there is disclosed a device to determine adherence of applied coating when loading thereof by tension, said device being characterized in that it consists of a test specimen formed by a ring (1) with a cylindrical or conical inner opening, a pin (2) with cylindrical or conical outer surface for inserting thereof into the ring (1) opening and a thread performed on the opposite side for inserting into the inner opening with a thread of a bar (5) and a tested coating (3) applied on a dace of the ring (1) and pin (2) assembly, a plate (4) for supporting the test specimen and a bar (5), wherein the apex angle ({alpha}) of the ring (1) inner surface and the pin (2) outer surface is in the range of 0 to 60 degrees, whereby the plate (4), which can be clamped into a general-purpose testing machine, has a transverse hole for free insertion of the bar (5) therethrough, wherein the bar (5) is provided at its one end with an axial hole with internal thread for fixing the thread of the pin (2) while at its other end it is provided with serrations for easy and unambiguous fixing of the bar (5) in opposite jaws of the general-purpose testing machine, whereby the ring (1), the pin (2), thee plate (4), and the bar (5) are made of metallic materials, whereby the half-finished product for the ring (1), the pin (2) and the bar (5) is a bar stock of circular cross section, whereby the half-finished product for plate (5) is a bar stock of rectangular cross section or a heavy-gauge sheet.

Description

Device for determination of tensile adhesion of sprayed coating

Technical field

The present invention relates to a device for determining the tensile adhesion of a sprayed coating and consists in its design, construction, manufacture and testing. The apparatus makes it possible to determine the tensile adhesion of a spray coating made of any material on a test specimen made of virtually any material, wherein the spray coating can be made by any of the technologies used.

BACKGROUND OF THE INVENTION

Hot spraying, also called hot spraying, eventually metallization or chipping, is one of the technologies of coating with special properties on the functional surface of components and products. The most common requirement is to increase its corrosion resistance. However, the aim of metallization may be to make an electrically conductive or non-conductive surface, a surface resistant to elevated temperatures, etc.

In practice, several methods of thermal spraying are used. All require a special application device called metallization guns. Hot spraying methods are usually classified according to the type of filler used (wire, rod, cord, powder, molten metal). Another criterion may be the nature of the operation. According to this aspect, metallization is divided into manual, mechanized or automated spraying. Another criterion can be classification according to the energy carrier (flame, arc, plasma, laser).

Regardless of the technology used to spray the material and the material from which it was made, it should be possible to evaluate its technological and physical properties. The technological properties include abrasion resistance, corrosion resistance, machinability, resistance to thermal shock, resistance to cyclic temperature changes, wettability and liquid absorption. Physical properties include hardness, bond strength, conductivity (thermal, thermal, electrical), modulus of elasticity and density. The above-mentioned properties can be determined for specific heat-spraying by appropriate tests (defined in domestic or foreign standards), namely non-destructive or destructive. The most commonly used non-destructive tests are visual inspection and evaluation, measurement of surface roughness, surface imprint, event. replica creation, surface crack detection, hardness test, coating thickness measurement, thermal and electrical conductivity determination. The most frequently used destructive test is metallographic examination of the thermal spray. Destructive methods are scanning electron microscopy, X-ray diffraction analysis, chemical analysis, bond strength testing (tensile test, bend test, grid test, chisel test), hardness test, abrasion test and thermal impact test. The choice of the type of test required depends on the particular case and the customer's requirement.

Adhesion is determined on test specimens sprayed or coated onto the product surface. When conducting the test on the test specimens, the test surface is applied to the face of one test specimen and then glued to the other specimen. This assembly is placed in a device capable of generating and recording a continuously increasing force. The test is terminated at the moment of the failure of the glued assembly. When performing a test on a coating sprayed onto the surface of the product, the sprayed coating is cut (cut through the annulus in the entire spraying thickness) with a special tool of defined diameter (thus giving a surface area of S [mm ² ]) up to the base material. A test target is adhered to the measured spot with a suitable adhesive. After the adhesive has cured, a tear-off device is attached to the test target, which tears the target away from the spray by continuous loading. During the test, the magnitude of the force F [N] required to detach the target is monitored. Adhesion is evaluated as bond strength σ [MPa] and is calculated from the equation

- 1 GB 304082 B6

F σ = -,

X as the force F [N] required to tear off the coating with an area S [mm ² ]. The test is terminated at the moment of the failure of the glued assembly.

The proposed apparatus for determining the tensile adhesion of the sprayed coating is based on a completely different principle. The test sample consists of a ring with a cylindrical or conical bore in the axis and a pin with a corresponding outer surface and a thread at the end. The apex angle α ranges from 0 to 60 °. The pin is inserted into the ring and the test surface is applied to the face of this assembly with the tested technology. The test sample thus prepared is then placed between the jaws of the universal testing machine with the help of other parts of the proposed device (plates and rods) and subjected to the axial loading test until it is destroyed. Obviously, no adhesive is required to determine the tensile adhesion of the spray coating.

SUMMARY OF THE INVENTION

The apparatus for determining the tensile adhesion of a spray coating according to the present invention consists of the following parts: a test sample consisting of a ring, a pin and a test spray, a plate and a rod.

SUMMARY OF THE INVENTION The object of the invention is to design, construct, manufacture and test a device for determining the tensile adhesion of a spray coating. The device makes it possible to determine the force required to destroy a test specimen under axial load. The purpose of the test is to determine the strength of the coating and / or the bond strength between the spray coating and the underlying metal.

Before testing, the ring and pin must be cleaned thoroughly. The pin is inserted into the ring and the test surface is applied to the face of this assembly using the selected spray method. A plate with a hole in the axle is inserted into the upper hinge slots of the universal tester to push the rod so that it protrudes slightly beyond the upper edge of the plate. The pin thread is screwed into the threaded hole at the top of the rod. This subassembly is placed on the top surface of the plate. The rod is knurled on its opposite lower part into the lower jaw of the universal testing machine, allowing the clamping of cylindrical samples. Then, the downward movement of the lower part of the universal testing machine is started and the course of the force is monitored as a function of its position. The test is terminated when the joint is destroyed, which results in a reduction in the instantaneous force value.

The advantages of the proposed device are above all a simple construction and the resulting easy production and low cost.

BRIEF DESCRIPTION OF THE DRAWINGS

The nature and function of the tensile adhesion determination apparatus of the spray coating according to the invention are explained by means of the drawings. Giant. 1 shows a view of all parts of the apparatus, FIG. 2 shows a detail of the test sample with spray, FIG. 3 shows the whole assembly during the test. The individual parts of the apparatus can be seen from the figures and the arrangement of the apparatus during the test is evident.

DETAILED DESCRIPTION OF THE INVENTION

The apparatus for determining the tensile adhesion of the spray coating according to FIGS. 1, 2 and 3 consists of the following parts: a test sample consisting of a ring 1, a pin 2 and a test spray 3, a test support plate 4 and a rod 5.

-2GB 304082 B6

Prior to the test, both ring 1 and pin 2 are carefully cleaned. Insert pin 2 into ring 1 and apply a test spray 3 to the face of the opposite thread of pin 2 with the selected hot spray method. 4. A rod 5 is pushed through the transverse hole in the plate v, the rod 5 having an outer diameter smaller than the diameter of the hole in the plate 4 so that it passes freely through the hole. The rod 5 is provided with an internally threaded axial bore at the end of the smaller diameter to secure the thread of the pin 2. At the other opposite end of the larger diameter, the rod 5 is knurled for easy and unambiguous mounting in the opposite jaws of the universal tester. Then, the downward movement of the lower part of the universal testing machine is started and the course of the force is monitored as a function of its position. The test is terminated at the moment of destruction of the test sample, which results in a reduction in the instantaneous force value.

The ring 1, the pin 2, the plate 4 and the rod 5 are made of metallic (ferrous and non-ferrous) materials, taking into account the nature and objectives of the test performed. Suitable semifinished products for their manufacture are commercially manufactured and supplied semifinished products, for ring 1, pin 2 and rod 5 of round cross-section, for plate 5 of rectangular cross-section or thick sheet.

The tensile adhesive device for spray coating can be used wherever it is necessary for any reason and for any purpose to determine the tensile adhesive strength of the sprayed material. Its advantages are simple construction, easy manufacture, low cost and good repeatability of test results.

Claims (3)

PATENT CLAIMS Device for determining the tensile adhesion of a spray coating, characterized in that it comprises a test sample consisting of a ring (1) with a cylindrical or conical inner bore, a pin (2) with a cylindrical or conical outer surface for insertion into the bore of the ring (1). ) and a thread on the opposite side for insertion into the inner hole with the thread of the rod (5) and the test spray (3) applied to the face of the ring (1) and pin assembly (2), the test specimen support plate (4) and rod (5), wherein the apex angle (α) of the inner surface of the ring (1) and the outer surface of the pin (2) is in the range of 0 to 60 °, the plate (4) being clampable to a universal testing machine and free passage of the rod (5), wherein the rod (5) is provided at one end with an axial bore with internal thread for fixing the thread of the pin (2) and at the other opposite end provided with a knurling m for easy and unambiguous fastening of the rod (5) in opposite jaws of the universal testing machine. Device according to claim 1, characterized in that the ring (1), the pin (2), the plate (4) and the rod (5) are made of metallic materials. Apparatus according to claims 1 and 2, characterized in that the blank for the ring (1), the pin (2) and the rod (5) is a rod of circular cross-section, the blank for the plate (5) being a rod of rectangular cross-section or thick sheet.