Dear Mr.  Abdulhadi Kadhum,

I hope that following links could help you in your researches.

Best regards, 

Dragan Vuksanović

http://www.mas.bg.ac.rs/_media/istrazivanje/fme/vol37/2/02_ffranek.pdf

https://www.hindawi.com/journals/ijme/2014/259129/

http://www.scihub.org/AJSIR/PDF/2011/1/AJSIR-2-1-99-106.pdf

http://www.asminternational.org/documents/10192/22533690/06358G_Sample_BuyNow.pdf/503ca4b8-353d-41e3-98cc-116d1a277cab

https://www.buehler.jp/solutions/technotes/vol3_issue3.pdf

https://www.ipen.br/biblioteca/rel/R36455.pdf

Dear Abdulhadi

You can use holographic interferometry to measure the wear rate as I did measure the corrosion rate by the following articles:

1-K.Habib,"Model of Holographic Interferometry of Anodic Dissolution of Metals in Aqueous Solution",Optics and Lasers in Engineering 18 (1993) 115—120.

file:///C:/Users/hp/AppData/Local/Microsoft/Windows/INetCache/IE/47MRHCJH/An%20article_19(1993).pdf

2-K. Habib.F. Al-Sabti. and.H. Al-Mazedi,"Optical corrosion meter",Optics and Lasers in Engineering,Volume 27, Issue 2, May 1997, Pages 227-233.

file:///C:/Users/hp/AppData/Local/Microsoft/Windows/INetCache/IE/F1JIQCTY/An%20article_48(1997).pdf

Dear Abdulhadi

Also, you can use even a simpler optical  method, just a simple optical microscope;(https://en.wikipedia.org/wiki/Optical_microscope)

in which you can optically examine the sample surface before the wear phenomenon occurs, by  setting up (moving)the objective lens to particular recording number (Ni)when the surface of the sample is in a focus image.  

Then, you can optically examine the sample surface after the wear occurs, i.e., metal removal,   In this case, the image of the worn out surface would be out of focus  if you used the initial set up of the objective lens of the optical microscope.  So, you can focus the image of the worn out surface by moving the set up of the objective lens to particular recording number (Nf).  

Thereafter, by subtracting Nf-Ni= you get the depth distance of the worn out surface (U), then you can use equation No.5            

                          A=wL=(V/U)                                      from

1-K.Habib,"Model of Holographic Interferometry of Anodic Dissolution of Metals in Aqueous Solution",Optics and Lasers in Engineering 18 (1993) 115—120.

(file:///C:/Users/hp/AppData/Local/Microsoft/Windows/INetCache/IE/47MRHCJH/An%20article_19(1993).pdf)

Where,

A is the surface area of the worn out sample.

w is the width of the sample.

L is the length of the sample.

V is the volume of the worn out of the sample.

U is the depth distance of the worn out surface of the sample.

By knowing the density of the material of the sample (d=m/V, in which m is the worn out mass of the sample) and the time took(t) for the removal of the mass, one can derive from equation No.5, the wear rate (W)as the following;

W=m/t=AdU/t=wLdU/t