Military Grade Silver Plating
ENS Technology provides complete electrodeposited silver plating services. We provide coatings to meet a variety of silver plating specs:
- FED QQ-S-365D
- ASTM B700
- AMS 2410
- AMS 2411
- AMS 2412
- Among other industry or company standards
Electrodeposited Silver Coatings
The silver electrodeposition process is used to provide uniform coatings on complex shapes, to improve wear and/or corrosion resistance, and/or to improve solderability on or for selected materials. Medical grade silver plating for the medical industry is suitable for temperatures up to 750°F, although wear and corrosion resistance may degrade as temperatures increase.
Electrodeposited silver can be applied to numerous different base materials, including:
- Steel
- Stainless steel
- Invar
- Aluminum
- Copper-Tungsten
- and other exotic metals
Classes & Grades of Silver Electrodeposition Plating
There are four (4) different classes and three (3) different grades of electrodeposited silver plating used throughout the industry to meet different specifications. The class of silver plating spec refers to the post-plating heat treatment process that is used; the grade of an electrodeposited silver plating refers to its thickness.
Types of Military Grade Silver Plating
Silver plating spec provides three unique types of silver electrodeposition, they include:
- Matte – Deposits without luster. It is comparable to those normally obtained from a silver-cyanide plating solution that is operated without the use of brighteners.
- Semi-Bright – Semi-lustrous deposits comparable to those normally obtained from silver-cyanide plating solutions operated with brighteners.
- Bright – Sometimes obtained by polishing or using brighteners.
Grade
Medical grade silver plating is graded either A or B. Grade A electrodeposited silver has received a supplementary tarnish-resistant treatment (chromate treatment), while Grade B silver plating spec has not received this treatment.
ASTM B700 Purity, Surface Appearance & Post Treatment Classes
The purity of ASTM B700 is determined as either 99.9% (Type 1), 99.0% (Type 2) or 98.0% (Type 3). The surface appearance of this silver plating spec is broken down into four different grades as follows:
- Grade A - Matte, no brighteners in plating bath
- Grade B - Bright, by use of brighteners in plating bath
- Grade C - Bright, by mechanical or chemical polishing of Grade-A
- Grade D – Semi-bright, by use of brighteners in plating bath
Post Treatment Classes
The post treatment of silver plating spec ASTM B700 is broken down into two classes as follows:
- Class N – No chromate treatment
- Class S – Added supplementary tarnish-resistant chromate treatment
Under-Plate Recommendations
Steel, zinc and zinc-based alloys on which silver electroplating is used should have a coating of nickel over copper under the silver. Nickel undercoats should be applied for silver plating on copper and copper alloys. When a nickel undercoat is not used on copper and copper alloy materials or when a copper undercoat is used on other materials, then the silver plating service should not be used for continuous service at a temperature more than 300 degrees Fahrenheit. The adhesions of the silver plating can be adversely affected due to a weak copper and silver inter-metallic layer.
The Right Solution for Your Medical Grade Silver Plating Specification
ENS Technology provides full-service electrodeposited silver plating for parts and components of all shapes and sizes. We require the following information from our clients prior to starting any electroless silver plating project:
- Full description of the base material
- The number/revision of the applicable electroless plating specification
- The required class/grade of the coating (plus service condition and type, if applicable)
- Various other information that deals with workmanship, inspection, and conformity of compliance to the specification
Quality Conformance Testing
Because each electroless silver plating specification has slightly different requirements for post-treatment quality control, we use a variety of quality testing methods, from naked eye testing to micrometer measurements to x-ray fluorescence processes. We have two advanced x-ray fluorescence systems in-house, which enables us to test platings during and after processing and allows us to provide immediate validation of coating thickness post-treatment.
Test coupons provided for quality testing must be of the same material and stock as the workpiece(s) to ensure that the specification is met.
Adhesion Testing
We provide adhesion testing to ensure that your silver electrodeposition meets your required specifications. Test coupons are bent to 180° over a mandrel with four times the thickness of the specimen. Adhesion test results are recorded by ENS Technology and kept on file at our facility for seven (7) years.
