Blistering during electroplating of electric heating tubes, poor adhesion

Apr 29, 2023

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2.3.1 Causes

(1) The potassium chloride content in the plating solution is too high;

(2) PH too low

(3) High cathode current density;

(4) Excessive brightener;

(5) There are many impurities in metal iron;

(6) The workpiece matrix contains silicon.

2.3.2 Processing methods

(1) Through analysis, add potassium chloride to the process specifications;

(2) Adjust the pH to the process specifications;

(3) Properly reduce the cathode current density;

(4) Use an appropriate amount of activated carbon to adsorb and filter;

(5) Process according to method 2.1.2 (6) above;

(6) By verification, prepare a mixed solution containing hydrofluoric acid for pickling. A solution of 300mL/L concentrated hydrochloric acid+20mL/L hydrofluoric acid (wHF=40%) can be used, where the hydrofluoric acid can dissolve and remove silicon containing compounds, completely activating the surface of the workpiece substrate.

2.4 Roughness and burning

2.4.1 Causes

(1) The zinc chloride content in the plating solution is too high (making the coating rough) or too low (easy to burn);

(2) The content of potassium chloride and boric acid is too low;

(3) PH too high (causing rough coating) or too low (causing burning);

(4) Insufficient brightener;

(5) There are many impurities in metal iron and copper.

2.4.2 Processing methods

(1) Adjust the zinc chloride content to process specifications through analysis;

(2) Add potassium chloride and boric acid to the process specifications;

(3) Adjust the pH to the process specifications;

(4) Add brighteners appropriately;