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Metal Surface coating methods: 12 replies,9605 views

#1
Metals exposed to the elements rust due to the chemical reaction of the elements, water and oxygen, and corrosive chemicals such as salt.

Efforts to preserve the metal in its original state were made by coating them with paint, and one of the earliest electro-chemical means is electroplating. Since then, new methods were implemented with higher precision as to the position and thickness of the coating and with various materials and targets.

Electroplating
Electroplating is the deposition of a metallic coating onto an object by putting a negative charge onto the object and immersing it into a solution which contains a salt of the metal to be deposited. The metallic ions of the salt carry a positive charge and are attracted to the part. When they reach it, the negatively charged part provides the electrons to "reduce" the positively charged ions to metallic form.

Diagram :


Anodization
Anodizing, or anodising, is an electrolytic passivation process used to increase the thickness and density of the natural oxide layer on the surface of metal parts. This process is of no use on carbon steel because rust puffs up and flakes off, constantly exposing new metal to corrosion. But on many other metals, anodizing increases corrosion resistance and wear resistance, and provides better adhesion for paint primers and glues than bare metal. Anodic films can also be used for a number of cosmetic effects, either with thick porous coatings that can absorb dyes or with thin transparent coatings that add interference effects to reflected light. Anodization changes the microscopic texture of the surface and can change the crystal structure of the metal near the surface. Coatings are often porous, thick ones inevitably so, so a sealing process is often used to improve corrosion resistance. The process derives its name from the fact that the part to be treated forms the anode portion of an electrical circuit in this electrolytic process. Anodizing can prevent galling of threaded components. Anodic films are generally much stronger and more adherent than most paints and platings, making them less likely to **** and peel. Anodic films are most commonly applied to protect aluminium alloys, although processes also exist for titanium, zinc, magnesium, and niobium.

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http://www.answers.com/topic/anodizing-1

Cathode Sputtering

CATHODE-SPUTTERING.��A typical cathode-sputtering system is illustrated in figure 1-16. This process is also performed in a vacuum. A potential of 2 to 5 kilovolts is applied between the anode and cathode (source material). This produces a GLOW DISCHARGE in the space between the electrodes. The rate at which atoms are SPUTTERED off the source material depends on the number of ions that strike it and the number of atoms ejected for each ion bombardment. The ejected atoms are deposited uniformly over all objects within the chamber. When the sputtering cycle is completed, the vacuum in the chamber is released and the wafers are removed. The masks are then removed from the wafers, leaving a deposit that forms the passive elements of the circuit, as shown in drawing at:




James OO7


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#2
Re: Metal Surface coating methods:
Replying to [James 007]:There is 'Rubber coating' as well..usually done on wires and rods.
Hard chrome plating is undertaken mostly on shafts and spindles.
#3
Re: Re: Metal Surface coating methods:
adseaco,

Yes, there is a host of coatings applied on to the metal surface. There are Epoxy coating, Anti-rust paint coating, rubber coating, elastomer coating and a process called vulcanization. (From the word VULCAN - Greek god of fire).

James OO7
#4
Re: Re: Re: Re: Metal Surface coating methods:
Replying to [MioBoy]:Galvanize in Zinc.
Thank you good neighbour.

Yet the hardness of the stongest metal is tungsten carbide, and the highest resistance to corrosion is titanium.

The molecules of the surface are bond together to form a smooth facade, without pores or valancy holes. That's the sulfur atoms which hardens the rubber and make it stronger and resistive to abrassive force.

OO7
#5
Re: Re: Re: Metal Surface coating methods:
Replying to [James 007]:Quite true [em18] I have had the opportunity to get most of these done, for my ***-bit jobs.
Lacquering, is undertaken to protect brass so that its shine remains for a longer period.[em7]
#6
Re: Re: Re: Re: Metal Surface coating methods:
Replying to [adseaco]:
I'm supprised that nobody has mentioned powdercoat. It's durable, quick, & looks great! (Granted if the steel is prepped correctly.)[em18] I'm promoting & manufacturing product, but one day I would love to open my own powder shop. It's been around for awhile, but some of the colors out there today are pretty impressive, Chrome powder I find especially interesting.
#7
Re: Re: Re: Re: Re: Metal Surface coating methods:
Replying to [brirey]:You should be aware that..James has mentioned..''Anti-rust paint coating'' in his earlier post...this covers ''power
coating'' [em14]
'Best of Luck'--- for your paint shop.
It is a tough work...believe me.I have gone through it.
I say this not to discourage but to be careful.[em14]
#8
Re: Metal Surface coating methods:
Replying to [James 007]:our company main supply veneer
#9
Re: Metal Surface coating methods:
Replying to [James 007]:
Your post is very informative. Metal protection is our number one concern on our projects for seawater desalination plants. But I don't get the relevance of this to scrap metals. Are there buyers who want the scrap coated for surface protections? Just curious..[em7]
#10
Re: Re: Metal Surface coating methods:
Replying to [jeddahprojects]:
Sixer, the moderator gives the permission.

The theme should be just "metals" not limiting to Scrap Metals. It widens the scope and makes it an interesting topic for discussion, keeping the spirit of the forum and the flame burning, like in the Olympics.

The is a liquid in room temperature classified as metal, it is Quicksilver or Mercury. If you were to observe the participation and interest in this forum is somewhat lesser than the other sectors.

Why was the Moby called a ****? ... an interesting question, I will raise it in another forum for the person who can give the most congenial answer gets a 100 MVP.

**** Moby
#11
Re: Re: Re: Re: Re: Metal Surface coating methods:
Quoting from [brirey]:


Replying to [adseaco]:

I'm supprised that nobody has mentioned powdercoat. It's durable, quick, & looks great! (Granted if the steel is prepped correctly.)[em18] I'm promoting & manufacturing product, but one day I would love to open my own powder shop. It's been around for awhile, but some of the colors out there today are pretty impressive, Chrome powder I find especially interesting.



DEAR BRIREY,

PLEASE KINDLY CONTACT US ONCE YOU HAVE OPENED YOUR POWDER SHOP. WE ARE A POWDER COATINGS MANUFACTURER FROM CHINA. BONDING POWDERS ARE OUR SPECIALTY PRODUCTS.

 

BEST REGARDS

JK YANG

WHEI-LEE POWDER COATINGS TECHNOLOGY INC.

T: 86-0752-3893888 (EXT:8023)

F: 86-0752-3893838

C: 86-13509231771

E: jhinkkoo@yahoo.com / zotani@shinetopgroup.com

W: www.shinetopgroup.com

 

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