Replacing AgCdO10 in contact rivets: suitable alternatives and technical evaluation
- Why AgCdO10 is being replaced in contact rivets
- Issues associated with AgCdO10
- Restrictions in the European Union
- RoHS, REACH and SVHC in the context of AgCdO10
- Requirements a replacement material must meet
- Selection criteria for engineers and procurement
- Alternatives to AgCdO10 in contact rivets
- AgSnO₂, AgNi and other materials in comparison
- How to implement the change in practice
- FAQ
Why AgCdO10 is being replaced in contact rivets
AgCdO10 was, for many years, a widely used contact material for contact rivets in relays, switches and other electromechanical assemblies. The material was used because, in many switching applications, it shows robust resistance to welding and, when properly designed, can achieve good results in terms of erosion behaviour and switching life.
Today, however, in many projects the focus is no longer solely on pure switching performance. In development, procurement and quality assurance, the question increasingly arises as to how AgCdO10 in contact rivets can be replaced by cadmium-free materials. The driving factor is, on the one hand, the material cadmium itself and, on the other hand, the growing uncertainty as to whether cadmium-containing materials should still be planned for new applications, target markets and product platforms.
As a result, material selection is considered more broadly than in the past. It is no longer only about whether AgCdO10 works technically, but whether a contact material can be sourced in series production over the long term, evaluated from a regulatory perspective and used in international markets. This is exactly why the targeted replacement of AgCdO10 in contact rivets is becoming more and more important.
For many companies, this topic is now no longer merely a question of individual projects but part of a general material strategy. Companies developing new product platforms today often try to prefer materials that are both technically robust and as broadly applicable as possible. Cadmium-free alternatives are therefore evaluated not only from a compliance perspective, but also with regard to long-term standardisation and reduced complexity.
Issues associated with AgCdO10
The technical evaluation of AgCdO10 must not be viewed in isolation from its material constituents. The material contains cadmium oxide and is therefore significantly more sensitive from a regulatory perspective than cadmium-free alternatives in the field of contact materials. In practice, this leads to increased effort for material approvals, customer audits, substance declarations and technical coordination along the supply chain.
In addition, cadmium-containing contact materials are no longer regarded as the preferred solution in many companies. Even if an existing application continues to be operated with AgCdO10, the material is often only of limited interest for new developments. Development departments therefore often try to switch early to materials that can be used in several markets and product lines with less qualification effort.
Another point is strategic platform capability. Anyone using AgCdO10 in contact rivets may, under certain circumstances, be tied to a material concept that must be reviewed again for later product variants. Cadmium-free materials are often easier to standardise in this respect.
From the customer communication perspective, AgCdO10 is also often more demanding. As soon as material lists, declarations of conformity or substance disclosures are requested, the coordination effort increases. This effort does not necessarily exclude the material, but it raises the barrier to its use in new projects. The more internationally products are marketed, the more relevant this point becomes.
Restrictions in the European Union
Within the European Union, the use of cadmium-containing materials is restricted in many areas. Whether AgCdO10 can be used in a specific product depends on the respective application, the field of use, the technical boundary conditions and, where applicable, on valid exemptions. Such evaluations are always case-specific.
For manufacturers of contact rivets and for device manufacturers, this means above all that the use of AgCdO10 must be carefully checked from a regulatory perspective. General statements are not reliable here. Particularly in new projects, in international supply chains or in products for different sales markets, this often leads to cadmium-free alternatives being preferred.
From the point of view of development and procurement, it is therefore not only decisive whether AgCdO10 could be technically usable. It is equally important whether the material can be evaluated, documented and classified towards customers with acceptable effort over the entire product life.
In practice, this is a major reason why AgCdO10 is now questioned much more critically than in previous product generations. Even if technical use may still be possible in individual cases, this alone is not a reliable argument for a stable long-term product strategy.
RoHS, REACH and SVHC in the context of AgCdO10
When evaluating AgCdO10 as a contact material, regulatory framework conditions play a central role in addition to technical requirements. In Europe, the RoHS Directive and the REACH Regulation are particularly relevant. Both sets of rules pursue different approaches, but together they influence the selection of suitable materials for contact rivets and other electrical contact parts.
RoHS and cadmium in contact materials
The RoHS Directive (Restriction of Hazardous Substances) restricts the use of certain hazardous substances in electrical and electronic equipment. Cadmium is one of the substances whose use is heavily restricted. Whether a cadmium-containing material such as AgCdO10 can be used in a specific application depends on the respective product category and possible exemptions.
In practice, these exemptions are often linked to specific technical applications and are subject to regular review. For manufacturers and procurement departments, this means that the use of AgCdO10 must not only be assessed technically, but should also be continuously monitored with regard to the regulatory situation. Long-term planning reliability is therefore limited in many cases.
REACH and SVHC substances
In addition to RoHS, the European REACH Regulation plays an important role. Under REACH, substances of very high concern, so-called SVHC substances, are identified and listed on a candidate list. These substances may be subject to additional information, notification and communication obligations along the supply chain.
Cadmium and certain cadmium compounds are particularly relevant in this context. For companies, this means that transparency regarding material contents must be ensured and communicated throughout the supply chain. This includes, among other things, material declarations, customer requests and documentation within product approvals.
Impact on material selection
In practice, this results in a clear trend: even if AgCdO10 may be technically suitable in certain applications, the material is increasingly assessed critically from a regulatory perspective. The effort for documentation, evaluation and communication rises, especially in internationally oriented product platforms.
Cadmium-free alternatives such as AgSnO₂ or AgNi offer advantages in this context, as they are often associated with lower regulatory effort. Even here, however, the specific suitability must always be evaluated on an application-specific basis and cannot be decided solely on the basis of regulatory aspects.
For engineers and procurement specialists, it therefore makes sense to incorporate regulatory requirements into material selection at an early stage rather than only considering them later in the project. This helps to avoid additional adjustments, reassessments and approval loops.
Requirements a replacement material must meet
Anyone wishing to replace AgCdO10 in contact rivets should not begin with a blanket material swap. First, it must be clear which function AgCdO10 fulfils in the specific application. Depending on the switching task, the critical point may lie in welding resistance, erosion behaviour, contact resistance, thermal stability or mechanical processability.
For contact rivets, current type, load characteristic, inrush current level, switching frequency, contact force, rivet geometry and carrier material are particularly relevant. A material that works well in a relay application can show significantly different results in another switching application. This is exactly why the selection of a replacement material should always be matched to the real load profile.
In practice, it is also important whether an existing rivet geometry is to be retained or whether design adaptations are possible. Some materials can be integrated into existing processes more easily than others. For a reliable transition, material, geometry and manufacturing process must therefore always be considered together.
In addition, not every technically plausible alternative automatically fits just as well into existing test and approval logic. A change of material can affect life tests, contact force windows, riveting processes and the assessment of the complete system. A replacement material should therefore always be viewed in the context of the full contact solution.
Selection criteria for engineers and procurement
In practice, selecting a suitable replacement material for AgCdO10 in contact rivets does not concern development alone, but always also procurement and quality assurance. Technical requirements and economic conditions therefore have to be considered together. An isolated material decision without coordination between these areas often leads to later adjustments or additional qualification effort.
Technical evaluation from the development perspective
For engineers, the function of the contact part is the initial focus. The decisive question is whether the replacement material can reliably reproduce the required switching behaviour under real load conditions. Welding resistance, erosion behaviour, contact resistance and thermal stability play a particularly important role here.
Furthermore, it must be evaluated how the material can be integrated into the existing design of the contact rivets. Geometry, contact force, mating contact and installation situation have a decisive influence on the result. In many cases, not only a material change is required, but also an adjustment of the entire contact solution.
Another important point is processability. The material must be integrable into existing manufacturing processes such as stamping, riveting or welding without impairing process stability. Especially at high volumes, this is a decisive factor for series capability.
Evaluation from the procurement perspective
From a procurement perspective, other issues come to the fore. In addition to material price, long-term availability is particularly relevant. A material should be stably procurable over the entire product life and should not serve only as a short-term alternative.
Standardisation capability also plays an important role. Materials that can be used in several applications or product lines reduce complexity in procurement and simplify stockkeeping. Cadmium-free materials often offer advantages here, as they can generally be used more easily in different markets and applications.
The supply chain must also be taken into account. This includes aspects such as lead times, minimum order quantities, supplier quality assurance and the availability of technical documentation. Especially where contact rivets are series components, stable and reproducible supply is essential.
Common decision basis
In practice, the best solution often emerges where technical and economic evaluation are brought together. A material may be technically suitable but not economically or logistically sensible. Conversely, a low-cost material may lead to increased wear or unstable switching behaviour in operation.
A sound material decision is therefore always based on a combination of application tests, manufacturing evaluation and economic consideration. The goal is a solution that not only fulfils the technical requirements, but can also be implemented stably in series production over the long term.
Alternatives to AgCdO10 in contact rivets
AgSnO₂ as a frequent alternative to AgCdO10
AgSnO₂ is one of the most important cadmium-free contact materials when AgCdO10 is to be replaced in contact rivets. The material is used in many switching applications, especially where a combination of welding resistance, erosion resistance and a regulatorily less critical material basis is required.
Within this material group, variants are often described by the tin oxide content, for example as AgSnO₂(10) or AgSnO₂(12). In practice, these designations refer to the approximate SnO₂ content in the material and serve as a guide for technical classification.
AgSnO₂(10) as a balanced material variant
AgSnO₂(10) is regarded in many applications as a balanced variant within the AgSnO₂ material family. The material often offers a combination of robust switching behaviour and comparatively manageable processability. This makes it suitable for numerous contact rivet applications where both functional requirements and manufacturing aspects must be taken into account.
From a technical point of view, AgSnO₂(10) can be particularly useful where a cadmium-free alternative to AgCdO10 is sought without extreme switching stress being the dominant factor. The material is therefore often used as a first candidate in evaluations.
AgSnO₂(12) for higher switching stress
AgSnO₂(12) is typically considered when greater robustness against critical switching conditions is required within the AgSnO₂ family. With increasing SnO₂ content, the material properties tend to shift toward greater welding resistance and more robust behaviour under demanding load profiles.
At the same time, however, differences can also arise in other areas, for example in contact resistance, thermal behaviour or forming and processability. For the design of contact rivets, this means that AgSnO₂(12) cannot automatically be used as a direct replacement for AgSnO₂(10) or AgCdO10 without checking the overall geometry and manufacturing process.
Evaluation in the context of contact part and application
For a sound material decision, considering the SnO₂ content alone is not sufficient. What is always decisive is the interaction between material, contact geometry, mating contact, contact force and the real load profile. Especially in the case of contact rivets, even small changes in the material system can have a noticeable effect on switching behaviour.
In addition, there is the manufacturing perspective. With increasing oxide content, requirements for formability, the riveting process and component geometry can change. AgSnO₂(10) and AgSnO₂(12) should therefore not be compared solely at material level, but always in the context of the complete contact solution.
Classification for replacing AgCdO10
When replacing AgCdO10, AgSnO₂(10) and AgSnO₂(12) represent two typical forms within a cadmium-free material family. AgSnO₂(10) is often selected as a balanced starting point, whereas AgSnO₂(12) tends to be considered when switching stress is higher and corresponding reserves are required.
Which variant is better suited in a specific case cannot, however, be determined in general terms. A sound decision always requires evaluation under real operating conditions and coordination with design and manufacturing process.
AgNi for balanced applications
AgNi is another important alternative when AgCdO10 is to be replaced in contact rivets. The material is known for good electrical conductivity, stable contact behaviour and proven processability. In many applications with moderate to medium loads, AgNi is a technically sensible solution.
Compared with AgCdO10, AgNi is particularly interesting where extremely pronounced welding resistance is not required, but low contact resistance and a controllable manufacturing process are important. For applications with high inrush peaks or highly critical loads, however, it must be checked case by case whether AgNi offers sufficient reserve.
AgZnO for selected switching tasks
AgZnO can also be considered as a replacement material in certain cases. The material is discussed where a cadmium-free solution with good welding resistance and erosion resistance is required. Whether AgZnO is suitable for contact rivets depends strongly on the specific switching task and the design concept.
In practice, this means that AgZnO can be an option, but it is usually not among the automatically first replacement candidates. Evaluation should always be based on application tests.
There is no universal one-to-one substitution
A central point in replacing AgCdO10 is that there is no universal material that delivers the same results in every application. The selection of an alternative must always be application-specific. Materials with similar switching characteristics can differ noticeably in manufacturing, contact mechanics or thermal behaviour.
AgSnO₂, AgNi and other materials in comparison
In many projects, the initial material evaluation comes down to comparing AgSnO₂ and AgNi. AgSnO₂ is often preferred when there are high requirements for welding resistance and switching life. AgNi is often attractive when balanced overall behaviour, good conductivity and stable process capability are the priority.
Within the AgSnO₂ material group, AgSnO₂(10) and AgSnO₂(12) are frequently evaluated in practice. AgSnO₂(10) is often regarded as the more balanced variant, while AgSnO₂(12) tends to be shortlisted for higher switching stress.
AgZnO may be evaluated in addition where the application requires a cadmium-free solution with robust switching behaviour and other materials do not fit optimally. However, which alternative is best suited cannot be derived from the material designation alone. The decisive factor is the interaction of material, contact geometry, mating side, switching load and mechanical installation situation.
For technical decisions, therefore, a comparison based on datasheets alone is usually not sufficient. The evaluation only becomes meaningful once sample parts are tested under real operating conditions.
How to implement the change in practice
The first step in a transition is a clean analysis of the previous application. It should not only be documented that AgCdO10 was used, but also why this material was originally chosen. Only from this can it be derived which property must absolutely be retained and where there is room for adjustment.
In the second step, suitable replacement materials are selected and tested in the same or an adapted rivet geometry. For contact rivets, in addition to electrical testing, the evaluation of dimensional accuracy, riveting behaviour, head formation and contact mechanics is often decisive. Especially in series applications, the transition should not be based on material datasheets alone.
In the third step, it must be checked whether the new material solution is also sustainable with regard to supply capability, approvals, documentation and manufacturing stability. For many applications, it makes sense not only to replace AgCdO10 formally, but to reassess the contact solution as a whole and specifically design it around a cadmium-free material.
A successful transition is therefore not just a material topic, but always a project involving material selection, design, manufacturing, testing and supply chain management. The earlier these areas work together, the more robust the later series solution will be.
FAQ on replacing AgCdO10 in contact rivets
Why should AgCdO10 in contact rivets be replaced?
The main reason is the cadmium content. This creates increased requirements in many projects regarding regulatory evaluation, documentation and material approval. In addition, cadmium-free materials are often preferred for new applications.
Which alternative is most often considered for AgCdO10?
In many cases, AgSnO₂ is evaluated first. The material is often considered an obvious cadmium-free alternative, especially where good welding resistance and robust switching behaviour are required.
Can AgNi replace AgCdO10 in contact rivets?
Yes, in many applications with moderate to medium loads. Whether AgNi is sufficient in a specific case depends on the load profile, the contact geometry and the requirements regarding switching behaviour and lifetime.
Is a one-to-one substitution of AgCdO10 possible?
Only rarely without further testing. In practice, the replacement material should always be evaluated in connection with switching load, rivet geometry, manufacturing process and overall part design.
What role do RoHS, REACH and SVHC play in material selection?
These regulations significantly influence the evaluation of cadmium-containing materials. They may lead to additional testing, documentation and communication obligations and are therefore a major factor when deciding in favour of cadmium-free alternatives.
Further technical information on contact materials and contact rivets can be found in the knowledge section. Where technical questions arise regarding the replacement of AgCdO10 in contact rivets, a technical consultation is advisable.
