Testing device and testing method for adhesive strength of inner hole coating

A testing method for adhesive strength of an inner hole coating, adopting a testing device for adhesive strength of an inner hole coating,

• wherein the testing device for adhesive strength of an inner hole coating comprises:
• a positioning assembly configured to clamp a sample to be tested;
• a guide ring disposed at a center position of the sample to be tested, wherein the guide ring has a threaded hole disposed along an axial direction of the guide ring and a guide groove disposed along a radial direction of the guide ring, the guide groove is communicated with the threaded hole;
• an assisting assembly, wherein one end of the assisting assembly is inserted into the guide groove, and another end of the assisting assembly is adhesive to the inner hole coating of the sample to be tested;
• a pull rod threadedly connected to the threaded hole, wherein the pull rod has a hollow interior, a bottom end of the pull rod has a tapered surface, the pull rod is configured to apply an axial tension to the inner hole coating via the guide ring and the assisting assembly, and apply a radial pressure to the inner hole coating via the tapered surface and the assisting assembly;
• a press rod slidably disposed in the pull rod and coaxially disposed with the pull rod;
• and
• a pull hook rotatably connected to the guide ring, wherein a bottom end of the press rod is capable of being abutted against one end of the pull hook, and another end of the pull hook is capable of being abutted against the assisting assembly, and the press rod is capable of applying a radial tension to the inner hole coating via the pull hook and the assisting assembly,
• wherein the testing method comprises:
• a preparing stage:
• pushing a pull rod inwardly along a threaded hole until a tapered surface abuts against a assisting assembly to apply a radial pressure to the assisting assembly via the pull rod, so that the assisting assembly is in close contact with the inner hole coating and keep in close contact with the inner hole coating for a set time, and resetting the pull rod;
• a tensile adhesive strength test:
• applying a axial pressure to a press rod, so that the press rod slides along the pull rod to abut against one end of the pull hook and the pull hook rotates relative to a guide ring, then another end of the pull hook is abutted against the assisting assembly, so as to apply a radial tension to the assisting assembly, and then the inner hole coating is subjected to the radial tension;
• and recording a magnitude of the axial pressure on the press rod at a moment when the inner hole coating is peeled off;
• and
• a shear adhesive strength test:
• applying an axial tension to the pull rod, so that the axial tension is transmitted along the guide ring to the assisting assembly so as to apply the axial tension to the assisting assembly, then the inner hole coating is subjected to the axial tension;
• and recording a magnitude of the axial tension on the pull rod at a moment when the inner hole coating is peeled off.