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What is the formula for calculating the amount of deposition layer on any metal per hour

Dear Sir

What is the amount of deposition of hardchrome on any metal in an hour? What is the formula for calculating the amount of deposition layer on any metal per hour or per load?

i am a Mechanical engineer and working in Hardchrome electroplating department. this is a new department for me as working position.

Can you please tell me that how to calculate the amount of deposition of layer in microns per hour? what is the formula of calculating the deposition of hardchrome layer on any metal per hour?

best regards.

Mohsin Siddiqui
Assistant Manager - Karachi, Pakistan
2007

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2007

Hello, Mohsin. Try to find a copy of the Metal Finishing Guidebook because it has a chart in the back which will give you the answers with very little calculation.

But the first principal is Faraday's Law, which is that 96,485 ampere-seconds will liberate one gram equivalent weight. So look up the atomic weight of chrome, and divide by its valence of 6 to find out how many grams will be deposited by 96,485 amp-seconds. Now if you know the density of chrome metal, you'll know how many cc's or ml's of chrome that is. And if you divide by the surface area, you'll know the thickness.

The chart in the guidebook takes these constants into account (atomic weight, valence, density), plus the number of seconds in an hour, and lets you simply read the ampere-hours required to deposit a thousandth of an inch thickness.

A monkeywrench in the works is that the calculations and charts assume 100 percent efficiency, that is, that all of the electricity deposits metal, whereas actually some of it is lost to the liberation of hydrogen. This fact is not much of an issue in efficient plating like silver or acid copper, but in chrome plating it is a huge monkeywrench because the efficiency is very very low. Maybe 15 percent. In fact, the somewhat famous proprietary HEEF 25 is famous for an efficiency of a glorious 25 percent :-)

Good luck!

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey