Can you tell me how the performance of trivalent chromium will compare to hexavalent chromium and what is needed to make the change? Recent regulations and performance requirements are making the switch from decorative hexavalent chromium plating to trivalent chromium plating a necessity.
With hexavalent chromium plating set to be eliminated in the European Union by , many manufacturers; especially global manufacturers, have already specified or are in the process of specifying trivalent chromium on their plans to meet the new regulations.
OSHA and the EPA continue to adopt legislation that further justifies switching from hexavalent to trivalent chromium plating. However, much hesitation still exists regarding the switchover to trivalent chromium due to concerns about performance, cost and the overall logistics of the conversion.
From a testing performance standpoint, trivalent chromium has already been used in exterior applications in the trucking industry for the past 30 years.
The field performances of trivalent chromium confirm test results performed by ASTM. From an operational performance standpoint, throwing power is much better with trivalent chromium. Trivalent chromium is also extremely forgiving with respect to current interruption this feature eliminates the occurrence of white wash commonly experienced with hexavalent chromium.
The advantages of improved covering power and uniform thickness have eliminated the need for use of auxiliary anodes for plating difficult geometries. When looking to make the transition from hexavalent to trivalent chromium plating, the best place to start is to recognize that not all trivalent chromium plating systems are equal.
It is best to research the variety of trivalent chromium plating processes available to match the one that will best meet your needs and that of your customers. You will want to evaluate finish color, speed, control, needed equipment and, perhaps most important, is the level service and support you will receive in advance of and during the conversion itself as well as after as you continue to work with the process.
The ingredients that we use for this process are chromium sulfate or chromium chloride. Importantly, it creates a more uniform coat and is an eco-friendly process. This is the main difference between trivalent and hexavalent zinc plating.
On the other hand, hexavalent zinc plating is the older version of zinc plating. The ingredients that we use for this process are chromium trioxide and sulfuric acid. It creates a less uniform coat and is harmful to the environment.
However, this process is less expensive, comparatively. The two major finishes of zinc plating are trivalent and hexavalent zinc plating. Wardell, Marcee. Trivalent Chrome Plating. Available here 2. Available here. With a mind rooted firmly to basic principals of chemistry and passion for ever evolving field of industrial chemistry, she is keenly interested to be a true companion for those who seek knowledge in the subject of chemistry.
Your email address will not be published. Leave a Reply Cancel reply Your email address will not be published. Chromium picolinate A. Hi Ritesh. Most governments consider hexavalent chromium to be carcinogenic certainly by inhalation, probably by touch, and possibly by ingestion , and everyone recognizes it as toxic.
Trivalent chromium is not considered toxic; in fact health food stores sell chromium picolinate as a supplement. Recently I was having chromium supplements to reduce extra weight. The product uses chromium piconilate. However, recently I noticed that the product is approaching its date of expiry.
I Wonder, knowing the potential carcinogenic effect of hexavalent chromium, that if there is a chance of alteration to hexavalent form. Hi Dipanjan. You and I don't know what the basis is for the expiration date so we probably shouldn't conjecture about the safety of expired product. But I don't think wither your medicine shelf nor your body will turn chromium piconilate into hexavalent chrome.
Nature doesn't usually do so either, but I can't rule out the possibility. If you put some chromium picolinate in a salt spray cabinet it will generate enough hexavalent chromium to register as positive using the 1,5-diphenylcarbohydrazide test. First a little background I have been obsessed with metallic finishes since the first time I saw a TarnX add on UHF channel 17 in Something where the dipped the blackened silver coin and antique sterling spoon in and it instantly glowed like a new mirror!
Since then, everything I owned, or was left unsupervised around, i. I am about to commit to a high end intensely scrutinized QC cosmetic plating operation, I am not afraid to go hungry, because I don't eat when there's more prepping or polishing to do, and have been through a thorough process of elimination from cost efficiency to personal preference conflicts, precise target market demographics as well as being truthful to myself about my weaknesses and recruiting outside help where needed as part of my list of realistic goals.
Is it your professional opinion, If I choose to plate using the latest trivalent chromium process, that someone with my OCD will be satisfied with if the planets are all in alignment? I know I know, it depends on what I'm plating, but I absolutely if the materials are available, can polish a turd! I can't find any specific literature.
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