SU1191730A1 - Method of manufacturing pickups by copper electroplating for checking cyclic deformations - Google Patents

Abstract

A METHOD OF MANUFACTURING SENSORS BY A GALVANIC COPPER METHOD FOR CONTROL OF CYCLIC DEFORMATION, which consists in the fact that the metal plate is subjected to galvanic copper plating in the electrolyte containing CuSO. and H.SO., remove the coating obtained from the plate and cut it into pieces, characterized in that, in order to simplify the method while increasing the sensitivity of the resulting sensors, copper plating is carried out in an electrolyte of the following composition: 125-250 g / l for CuSO ( j-5H20, 20-70 g / l in H, S04 at a current density of 100 A / m to the limiting cathode diffusion current density and temperature to obtain a coating 5-30 microns thick (P oa

Description

one .

This invention relates to a measurement technique for monitoring the level of fatigue damage accumulated in machine parts under cyclic loading by electroplating.

The purpose of the invention is to simplify the method while simultaneously increasing the sensitivity of the resulting sensors.

FIG. I shows an installation diagram for implementing the method; in fig. 2 - experimental test data of sensors manufactured by the proposed method in comparison with known data.

The installation contains an electrolyzer 1 with a cylindrical anode 2 and a cathode 3 placed in it, which are connected to a source 4 of a constant controlled current. In addition, an ammeter 5 is connected to the circuit. A DC electric motor 6 provides for the rotation of the cathode 3 at a variable speed. Thermostat 7 maintains a constant predetermined electrolyte temperature during electrolysis.

The method is carried out as follows.

According to the generally accepted methodology, an electrolyte is prepared, choosing a concentration. SHjO within 125250 g / l, H2S04 20-70 g / l, and a cylindrical electrolyte 1 is filled with it. Electrolytic copper is made. A cylindrical hollow anode 2 with a diameter of 5-15 mm is smaller than the diameter of the electrolyzer 1. Anode 2 degrease , pickled, rinsed with distilled water and placed in the electrolyzer 1. The cathode 3 is made in the form of a stainless steel cylinder, the surfaces of its bases, on which the copper coating is not applied, are insulated with plastic overlays. The side work surface with an area of 0.5 and more grind, degrease, wash. After this, the cathode 3 is fixed on the drive axis of the electric motor 6 and placed in the electrolyzer 1 of the end of the die to the anode 2. The cathode 3 is driven during rotation at a fixed speed, which ensures the establishment of the same hydrodynamic mode over the whole working surface

carry This increases the uniformity and reproducibility of the resulting coating over the entire area. In addition, the rotation of the cathode 3 allows to increase the allowable current density and, consequently, the performance. Galvanic copper plating is carried out at fixed values of temperature and current density selected within 3-40 ° C and 100 A / m2, respectively, the cathodic diffusion current density. The latter is determined by a known method. in advance in preliminary experiments.

The electrolysis is carried out to obtain a coating 5-30 microns thick.

At the end of the electrolysis, the coated Cc cathode is removed from the electrolyzer 1, rinsed with distilled water and dried with a stream of cold air. The resulting copper coating is removed from the cathode 3 and cut into separate parts, used as sensors.

Examples of the results of experimental tests of sensors manufactured by the proposed and known methods are presented in FIG. 2 in the form of graphs of dependences between the limiting deformation of the appearance of the first spots, which is a criterion of the sensor sensitivity, and the number of cycles of alternating voltages N. The experimental samples were made of steel 45 (GOST 1050-74), the surface finish of the samples was RO 0.16-0.19 µm. The shear modulus was 2 Ju MPa.

Curve 1 in FIG. 2 corresponds to sensors manufactured by a known method, curves 2-7 manufactured by the proposed method in various conditions: 2 corresponds to copper plating in the CuS04-5H5iO electrolyte — 200 g / l and 50 g / l at a current density of 2800 A / m (limiting cathodic diffusion current density), coating thickness 10 µm; 3 - CuS04 5H2iO 250 g / l, - 70 g / l, temperature and current density 800 A / m, coating thickness 5 µm; 4 - Cu SO 4. 5HiO - 250 g / l, - 70 g / l, temperature 25 ° C and current density 800 A / m, coating thickness 30 µm; 5 - CuS04-5H2 0 - 125 g / l, 20 g / l, temperature and dense

Claims (1)

METHOD FOR PRODUCING SENSORS BY THE METHOD OF GALVANIC COPPER FOR CONTROL OF CYCLIC DEFORMATIONS, namely, that the metal plate is subjected to a method characterized in that, in order to simplify the method while increasing the sensitivity of the obtained sensors, copper plating is carried out in the electrolyte of the following composition: 125-250 g / l ^ -S ^ O, 20-70 g / l in H, SO ₄ at a current density of 100 A / m ^g to the limiting cathodic diffusion current density and a temperature of 3-40 ^ C to obtain a coating with a thickness of 5-30 μm. I91730 F # g. ^{1 1 1}