A crate of parts is returned by the customer’s client. The coating is flaking off along the edges of a handful of parts. Not on all of them, just some of them. And so begins a job that no purchaser has factored into the budget.
The supplier of the electroplated undercoat has submitted its report. The layer thickness is within tolerance, the bath analysis is satisfactory, and the batch has been released in accordance with the procedure. The supplier of the PVD coating has submitted their report. The chamber operated according to the programme, the workpieces were cleaned in accordance with the standard, and the test specimens passed the adhesion test. Both reports may be correct, yet the parts are still defective.
When a hybrid coating fails at two suppliers, the cause often lies in the interface between the layers, which neither of them owns. At Chem-Tec Plating, the electroplated or chemical undercoat and the PVD top coat are applied in the same building in Uldum, under a single ISO 9001 quality management system. Consequently, there is a single failure analysis, a single dataset and a single supplier who takes full responsibility for the entire coating.
What is a hybrid surface?
A hybrid coating combines two processes on the same workpiece. First comes a galvanic or chemical undercoat, typically nickel or chemical nickel, which provides corrosion protection. On top of this is a PVD coating of 0.1 to 4.0 µm, which provides the hardness and the final finish in chrome, black chrome, gold, brass or copper.
This combination is used where a surface needs to look flawless whilst also withstanding everyday use. Fittings, handles, components for the automotive industry and professional audio equipment are typical examples. Each process fulfils its part of the task, but the result stands or falls on the two layers being properly bonded together.
Why do two suppliers end up pointing the finger at each other?
Because the error is often in a place that none of them have signed off on.
Each supplier works to its own specifications. The electroplating supplier guarantees a specific layer thickness and surface quality when the parts leave the premises. The PVD supplier guarantees a specific result on the parts that arrive. Between these two guarantees lie packaging, transport, storage, incoming inspection and a new pre-treatment process.
The adhesion between the layers depends on the condition of the surface at the moment the PVD process begins. This condition is not specified in either of the two specifications. When the coating subsequently peels off, both suppliers have documentation proving that they delivered what was agreed.
For the purchaser, the cost rarely comes in the form of an invoice. It takes the form of laboratory analyses and weeks of emails going back and forth, whilst in-house production is held up waiting for parts. In the worst-case scenario, it comes in the form of a complaint from an end customer who couldn’t care less which subcontractor was in the right.
What can Ford and Firestone teach a procurement professional about shared responsibility?
Few supplier relationships have been closer than that between Ford and Firestone. Henry Ford and Harvey Firestone were personal friends, and their collaboration dated back almost a hundred years. The families had even become intermarried. Ford’s chairman in 2001, William Clay Ford Jr., was the great-grandson of both men.
In August 2000, Bridgestone/Firestone recalled around 6.5 million tyres, many of which were fitted to Ford Explorers. Ford believed the fault lay with the tyres. Firestone believed that the Explorer’s design was part of the explanation, and that Ford was unwilling to look into it. In May 2001, Firestone announced that the company would no longer enter into new tyre agreements with Ford in North and South America. The following day, Ford announced that it would replace a further 13 million Firestone tyres at an estimated cost of 2.1 billion dollars.
The fault lay in the interaction between a tyre and a car, and neither party was to blame for that interaction. Not even a relationship spanning almost a hundred years or family ties could withstand that question.
A hybrid system is far less dramatic, but the problem is the same. When two components from two different companies are required to work together, both may meet the specifications, yet the system as a whole fails.
How does Chem-Tec Plating handle a complaint regarding a hybrid coating?
We carry out both nickel plating and PVD coating in the same building. The workpiece does not leave the premises between the nickel plating bath and the vacuum chamber, and both processes are carried out under the same quality management system. We have been ISO 9001-certified since 2009 and were upgraded to ISO 9001:2015 in 2018.
This turns the complaint into an analysis rather than a negotiation. The quality department has process data and approvals from both stages collated in one place. It can track an item from the initial pre-treatment right through to the finished coating without having to ask another company for access to anything at all.
Every morning, the quality, production, development and sales teams meet to review the current production projects. Any complaints are therefore dealt with by staff who are familiar with both processes, rather than by a contact person who would first have to pass them on. All data is stored to ensure that the same error does not recur. If an operator notices anything about the workpieces that could compromise the result, we contact the customer before proceeding.
Errors can still occur. The difference is that there is only one number to ring, and the person who answers the phone is responsible for the entire booking.
What should a purchaser ask before ordering a hybrid surfacing?
If you’re currently experiencing under-fulfilment and PVD with two different suppliers, there are five questions worth asking before the next complaint comes in.
- Who is responsible for ensuring the adhesion between the two layers, and is this set out in an agreement?
- What happens to the items between the two processes, and how long are they held for?
- What process data can each supplier provide, and can it be linked to the same batch?
- Who carries out the fault analysis if the surfacing comes loose, and who pays for it?
- How long did it take to resolve your most recent complaint, and what did you spend the time on?
If both suppliers answer “we do” to the first question, neither of them actually does so in practice. Your current suppliers are probably doing their job well. The weaknesses lie in the way the task is broken down.
What happens when responsibility is centralised in one place?
Imagine the next box of returned parts. Instead of two reports, there will be just one. It will describe what happened in the sub-coating stage, what happened in the PVD chamber, and how the two stages affected each other. It does not point the finger at any other company, because there isn’t one.
The designer receives a single specification covering the entire flooring project, and the purchaser has a single supplier to audit and a single contract to manage. The quality manager can trace the next fault back to its root cause rather than to an email thread.
The benefits grow over time. Every complaint that is resolved in days rather than weeks frees up time in your own quality assurance department. And the lessons learnt from this remain within a single system, rather than getting lost between two.
How to get started
Please send us a drawing and a specification for a component that is currently having its undercoating and PVD treatment carried out by two different suppliers. Our specialists will get back to you with an assessment of how they would combine both stages into a single process, and what changes this would entail to your specification. Please write to info@chemtec.dk or call +45 75 67 92 92.
A hybrid surface consists of two layers, but the customer only perceives a single surface. It is reasonable that liability should follow the same logic.
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