FAQ
Characteristics or cemented carbide
What is the relationship between hardness and strength?
Hardness affects resistance to abrasion, and harder materials are more resistant to abrasion.
However, this resistance is not only about hardness, but also can vary based on adhesion, despite the quality of the material.
Thickness also affects the life of material, and so the environment and manufacturing process must be taken into consideration when selecting cemented carbide grade.
There are many factors related to strength, such as transverse rupture strength, impact strength, Fracture toughness value etc., requiring a selection based on each of those factors.
We look forward to hearing from you about your cemented carbide selection.
However, this resistance is not only about hardness, but also can vary based on adhesion, despite the quality of the material.
Thickness also affects the life of material, and so the environment and manufacturing process must be taken into consideration when selecting cemented carbide grade.
There are many factors related to strength, such as transverse rupture strength, impact strength, Fracture toughness value etc., requiring a selection based on each of those factors.
We look forward to hearing from you about your cemented carbide selection.
Are there any changes due to thermal conductivity?
Cemented carbide changes based on the amount of Co. Lower Co levels lead to higher conductivity.
Generally, higher conductivity means that heat escapes well and frictional heat can be controlled.
We look forward to hearing from you about your cemented carbide selection.
Generally, higher conductivity means that heat escapes well and frictional heat can be controlled.
We look forward to hearing from you about your cemented carbide selection.
How do you store cemented carbide products?
For cemented carbide materials:
Room temperature is fine. (Less than 300℃, as cobalt oxidizes at that temperature)
Humidity leads to rusting, so we recommend storing in an area with low humidity.
For complete metal molds:
Cemented Carbide corrosion can occur from grinding fluid, lubricating liquid, or other liquids.
If the grinding or lapping surface is not stored properly, corrosion may occur. Store using a slushing oil or rust-inhibitor.
Room temperature is fine. (Less than 300℃, as cobalt oxidizes at that temperature)
Humidity leads to rusting, so we recommend storing in an area with low humidity.
For complete metal molds:
Cemented Carbide corrosion can occur from grinding fluid, lubricating liquid, or other liquids.
If the grinding or lapping surface is not stored properly, corrosion may occur. Store using a slushing oil or rust-inhibitor.
What are the effects of corrosion?
We checked some cemented carbide made 20 years ago, and there 20 microns worth of corrosion.
Only the surface was corroded, so we were able to remove it by reprocessing it.
Due to working environments, some corrosion cannot be removed, so we recommend regrinding if the corrosion is 0.1mm or greater.
If storing after regrinding, ensure that all processing liquids have been removed and dried. Wrap the carbide in a rust-inhibitor and cover in slushing oil, or cover in alumina powder.
Only the surface was corroded, so we were able to remove it by reprocessing it.
Due to working environments, some corrosion cannot be removed, so we recommend regrinding if the corrosion is 0.1mm or greater.
If storing after regrinding, ensure that all processing liquids have been removed and dried. Wrap the carbide in a rust-inhibitor and cover in slushing oil, or cover in alumina powder.
There was a 50% change in volume.
Carbide is a material made by compacting powder during sintering, and there are crevices inside the carbide where air and particles collide.
Through sintering, the cobalt liquefies, and a 50% reduction in volume occurs when tungsten particles are attracted due to the capillary phenomenon. The connecting points for different powdered particles try to mix and homogenize, inducing the atoms to move in an attempt to create new compounds.
Through sintering, the cobalt liquefies, and a 50% reduction in volume occurs when tungsten particles are attracted due to the capillary phenomenon. The connecting points for different powdered particles try to mix and homogenize, inducing the atoms to move in an attempt to create new compounds.
Why does the amount of Co and WC particle size have an effect on the thickness of the altered layer?
It is thought that when Co is in large quantities, the fusing point is lowered, increasing the amount that melts and thickening the altered layer.
It is also thought that when WC particle size is small, the material becomes easier to melt due to the volume effect, which thickens the altered layer.
It is also thought that when WC particle size is small, the material becomes easier to melt due to the volume effect, which thickens the altered layer.
Carbide Material Selection
I'd like to extend the life of my carbide tool with a high speed press.
We recommend lapping the cutting edge.
The glide can be improved and abrasion can be softened by increasing the surface roughness.
Everloy, we can promise a surface roughness of less than 0.3S that maintains accuracy through whetstone lapping, even with different shapes.
We look forward to hearing from you about Precision Processing.
The glide can be improved and abrasion can be softened by increasing the surface roughness.
Everloy, we can promise a surface roughness of less than 0.3S that maintains accuracy through whetstone lapping, even with different shapes.
We look forward to hearing from you about Precision Processing.
What materials do you recommend for punches, dies, and strippers?
There is no particular material that we recommend, as each user and circumstance has different needs.
EF10 for punches, and KD20 for dies are commonly used.
Ultra fine grain cemented carbide may not be suited (due to electrolytic corrosion, etc.) for wire processing for strippers and the cutting edge of dies. We look forward to hearing from you about your cemented carbide selection.
EF10 for punches, and KD20 for dies are commonly used.
Ultra fine grain cemented carbide may not be suited (due to electrolytic corrosion, etc.) for wire processing for strippers and the cutting edge of dies. We look forward to hearing from you about your cemented carbide selection.
What carbide has superior chipping and abrasions resistance for cutting and bending for C5191, C5210 (phosphor bronze), and C1020 (pure copper)?
What about working with pure iron, pure copper, and nickel?
Cobalt contained in carbide and its affinity to the processed material is the factor that result in a shorter lifespan.
At Everloy, we have received great praise for our MC20 that controls this adhesion. We look forward to hearing from you about your cemented carbide selection.
At Everloy, we have received great praise for our MC20 that controls this adhesion. We look forward to hearing from you about your cemented carbide selection.
We are using fine grain and ultra fine grain carbide parts with wire cutting and EDM machines, but chipping occurs often during use.
We are using carbide for press processing of stainless materials, but compared to SPCC, abrasion occurs quickly and parts must be replaced.
Stainless materials are hard and viscous, which leads to greater abrasion and chipping.
We recommend using KX01, as it has superior toughness and resistance to heat, and is extremely hard.
We recommend using KX01, as it has superior toughness and resistance to heat, and is extremely hard.
Which carbide material is the most resistant to abrasion?
Can A10W be considered for use in electrical machining?
We believe A10W can be used safely even in electrical machining.
Fine particle grain cemented carbide inhibit crack propagation through mixing coarse grain grade, and the altered layer's thickness is reduced through lowering the amount of Co. This is why we recommend A10W for wire EDM.
Fine particle grain cemented carbide inhibit crack propagation through mixing coarse grain grade, and the altered layer's thickness is reduced through lowering the amount of Co. This is why we recommend A10W for wire EDM.
Manufacturing Process
| Q1: | I want add a tap to carbide parts. |
|---|---|
| Q2: | Can a magnet be attached during processing? |
| Q3: | What's the difference between EDM cracks and altered layers? |
| Q4: | About soft metal burning. |
I want add a tap to carbide parts.
We recommend direct tapping. Tapping is done after taking into account the amount of shirking that will occur during sintering.
It is tougher than electrical tapping or bush brazing.
If pitch accuracy is required, we recommend electrical tapping or brazing.
It is tougher than electrical tapping or bush brazing.
If pitch accuracy is required, we recommend electrical tapping or brazing.
Can a magnet be attached during processing?
While carbide is magnetic, it is weak, making magnetic chucks dangerous.
We recommend using a vice, reinforcing plate, or bonding adhesive.
We recommend using a vice, reinforcing plate, or bonding adhesive.
What's the difference between EDM cracks and altered layers?
Both occur from thermal energy during EDM. An altered layer is made of melted and solidified Co and WC particles, and a crack occurs from EDM impact or the stress of shrinkage from melting and solidifying.
An altered layer occurs only on part of the processed layer, but a crack may occur through the original material, as well.
An altered layer occurs only on part of the processed layer, but a crack may occur through the original material, as well.
About soft metal burning.
Using metal molds with metal adhered to the mold, frictional heat occurs, part of the metal melts, and burning will occur.
Soft metals are more likely to adhere and burn.
Adhering: the bonding that occurs when 2 types of metals approach one another at the atomic level
Burning: the state when the friction factor increases suddenly from adhering or welding
Affinity mechanism: 1) Adhering > Burning > Affinity 2) Burning > Affinity
Soft metals are more likely to adhere and burn.
Adhering: the bonding that occurs when 2 types of metals approach one another at the atomic level
Burning: the state when the friction factor increases suddenly from adhering or welding
Affinity mechanism: 1) Adhering > Burning > Affinity 2) Burning > Affinity
Other Questions
| Q1: | How is lot management carried out? (Frequency of checks on carbide structure?) |
|---|---|
| Q2: | Do I need to wait longer for Micro-grain cemented carbide? |
How is lot management carried out? (Frequency of checks on carbide structure?)
A test piece which is sintered with product is inspected its structure and hardness.
We check every single lot of powder when it is completed. We check the external appearance of all products when sintered and inspect the structure of a sample by random inspection.
We check every single lot of powder when it is completed. We check the external appearance of all products when sintered and inspect the structure of a sample by random inspection.
Do I need to wait longer for Micro-grain cemented carbide?
No.
At Everloy, thanks to our Micro-grain cemented carbide EF grade assembly line, we are able to deliver in the same time as other materials.
At Everloy, thanks to our Micro-grain cemented carbide EF grade assembly line, we are able to deliver in the same time as other materials.