MaXXshot is an exclusive duplex process from Prolong for severe die cast applications.
MaXXshot gives Die Cast tooling the best combination available to reduce maintenance costs and extend tooling life.
MaXXshot can be applied to any Die Cast Tool, but was developed for:
Gate Areas / Heavy Washout Areas / Critical Inserts
How much build-up will I see with MaXXshot?
MaXXshot will add 5-8 microns of thickness (.0002-.0003”) per side. Extensive studies have found this thickness level to be optimal for die casting applications.
NOTE: Solvenite alone creates no size change.
What kind of results have you documented?
Customers have reported 10x the life on gate inserts (compared to untreated) and has been outperforming all other common duplex coatings 4x or more.
Very effective against severe washout (gate areas) and solder, even in the most demanding die cast applications.
MaXXshot Duplex Process:
- Solvenite Deep Diffusion is the first step, and the KEY to MaXXshot’s success. Solvenite diffuses deep (.015- .020 case depth) with no white layer. This adds compressive strength and ductility, protecting die steel during thermal expansion and contraction. Solvenite creates an oxide free surface, perfect for our “hard metal coating” which is deposited on the surface for the second step of our duplex process. The ability to achieve superior adhesion eliminates chipping / flaking, which is common with other duplex coatings
- Solvenite treated tooling is then coated with a thin, hard top coating that is a matrix of: 1) Tungsten, 2) Chromium, 3) Titanium. Our top coating significantly helps with solder and is extremely hard (3500mv) to protect from gate erosion.
WHY DOES ALUMINUM REACT MORE STRONGLY WITH NITROGEN THAN CARBON, AND WHAT DOES THIS MEAN FOR THE SURFACE INTEGRITY OF TREATED H13 STEEL? ⇣ EXPAND ⇣
First, let us state that Aluminum reacts strongly with nitrogen in steel. There are other components in the steel that can react, such as chromium, but aluminum is the strongest reactor. If so, why is it common to Nitride die cast steel before the aluminum injection process? The reason is because aluminum nitrides form inside the steel structure, and expand. This puts the surface of nitrided steel under compression, which can be a good thing in the case of nitriding steels.
During the aluminum injection molding process, the same chemical reaction takes place, but with the aluminum and nitrogen coming from different places. An H13 tool steel who’s surface has been heavily nitrided will react with molten aluminum diffusing into the system to form the same types of aluminum nitride compounds. When this occurs, the same expansion occurs, but in an uncontrolled manner, leading not only to surface compression, but cracking as well.
Aluminum reacts with nitrogen compounds. The heat of formation for aluminum nitride is -76.47 kcal/mol while the heat of formation for aluminum carbide is -49.7 kcal/mol, both at 298.15 K. These numbers are only somewhat useful, as they depend upon many factors and assumptions including room temperature. But the aluminum nitrides lower delta G value means it is thermodynamically favored to form compared to aluminum carbide.
The reasons for this basic phenomenon gets us to the atomic level of where the effects of atomic sizes, bond structure, electronic valences, and crystalline shape all interact to result in a general reaction strength and mechanism that is indicated by the heat of formation value mentioned above.
The process of stopping the reaction of molten aluminum with an H13 surface is essentially the process of stopping the chemical reaction of aluminum with the H13 and the nitrogen added to its surface. It is a general principle in chemistry that pure materials tend to undergo chemical reactions much better than impure materials. Hence impurity, or positively stated, “alloy-complexity”, can lead to significant reductions in rates of these adverse chemical reactions. The reasons for this are numerous, but among them are steric interferences, where two chemicals cannot react because a third chemical physically blocks them from contact, and reaction spoiling effects, where a new crystal starts to form, but an impurity enters the structure and the shift in crystalline shape prevent further reaction.
It should be noted, before one errantly concludes to either not treated the H13, or simply carburize the H13 surface, that the aluminum will react very quickly with an H13 surface that has no nitrogen present and a purely carburized H13 is not as hard or stable. Solvenite’s combination of elements is what is essential for success.