Q & A

Below you will find a list of commonly asked questions. Simply click the question to view the answer for Alphas-V (TD).  

Q&A for Alphas-C is coming soon.   Please contact us or e-mail us if you have any questions.


All we ask is you use up to a #320 grit finish on the working surface of the die. U.S. Kondo will take care of the rest of the polishing work, with up to a 1 micron or better finish. It is essential that the die surface is prepared properly prior to the Alphas-V process for maximum performance. Our expert die polishers will finish up quickly, beautifully and most importantly professionally.
Yes, we can remove any kind of coating such as TD, PVD, or CVD effectively and safely. Regarding TD coating removal, we have an unique coating removal method, which minimizes surface damage. We will request customers to specify the name of the previous coating used on the die. This information helps us to determine which removal method is needed and speeds up the process. U.S. Kondo can also give a better estimate as to when you will receive your dies back with Alphas-V coating.
We remove whatever the coating thickness is and .001-.0015” polishing down to obtain a mirror finish die surface.
Alphas-V(TD) has a beautiful deep or blackened shinny steel color with a lap finish after the coating, but the surface looks black without lapping finish. This black top layer is built up over the VC layer due to a reaction with oxygen right after it was pulled up from molten salt furnace into the air. The depth of reaction is within a unit of angstrom, so it shouldn't affect the quality and performance of Alphas-V. The color will also change to light blue or to a yellowish oxidized color after post hardening (vacuum hardening after the process enhances the substrate hardness), which does not effect the quality of the coating either.
It is very easy. Just grab a small file or a piece of sand paper and push into it. If the sandpaper slips and doesn’t have any resistance, then the hard layer still exists. Applying copper sulfate is also an easy way to find if Alphas-V is still on the die's surface because copper (Red Color) will educe wherever the coating is missing.
As long as the die can fit in the TRD pot (∅18” X 40”) it can be processed. There is no minimum size limitation.
Certainly, the TRD process will apply “Hardening” and “ Coating” simultaneously. You can finish machining dies as Green, which can save time & cost. We also can consult with you about pre-coating dimension.
No, TRD can be coated over any steel, cast iron, nickel, cobalt, or cemented carbide containing more than 0.1% carbon. Further, those different materials can be processed at the same time as long as the required processing temperature is the same. CVD and PVD coatings must be charged with the same material, which can sometimes cause longer turn arounds, quality issue, or turning down customer’s order.
Yes, it can be coated. TD has been used for millions of automotive parts and machine components in Japan, and even used for some type of dies.
Our coating furnace is operated at the same temperature as the hardening temperature of steel. The hardening process takes in place when it is quenched in the air, in the salt, or high temp oil furnace in order to reduce possible material distortion. However those quenching methods would not be sufficient to harden Oil/Water quenching steel, as they need to be rehardened in a non-oxygen atmosphere furnace or carburized atmosphere furnace. Most machines are processed with this procedure.
The tool steel technology is always progressing. 10-20 years ago, D2 was replacing D3 all over the world, and now D2 is being replaced by new innovative tool steel, such as 8% Cr tool steel, currently being used Europe and Japan due to better machinability, toughness, and hardenability. DC53 is the most popular 8% Cr tool steel and U.S. Kondo recommends DC53 for the usage in severe forming die applications.
Carbide grains distributed in the PHS microstructure are very consistent and extremely fine. PHS' carbide grains provide better mechanical properties and reduce the risk of distortion, however there are many factors which causes distortion. It is not recommended to use PHS without solving other distortion factors first due to PHS's high cost.
PHS could obtain sufficient hardness through the Alphas-V process. PHS without cobalt's hardness goes up to HRC61-62 and PHS containing cobalt's hardness goes up to HRC67-69.
High vanadium content will not improve Alphas-V’s performance. In fact, if the vanadium content is more than 3-4%, tool steel's machinability and grindability will deteriorate. Steel containing 5.10.15% of vanadium will cost a tremendous amount of money and take time to grind and polish. Furthermore, High V steel is low on elasticity and high on cost. Only applications where wear resistance is important might see some benefit in using High vanadium steel. Our coating will be 100% vanadium over the entire surface, so there is no reason to use steel containing vanadium.
Unfortunately cemented carbide isn’t suitable. When Alphas-V or the CVD process is applied to cemented carbide, a chemical compound called “W2C” is generated under the carbide layer, which makes the cemented carbide brittle. The process applied and negative effect of mechanical strength would depend upon the kind of cemented carbide. Cemented carbide must be selected very carefully, please contact U.S. Kondo for details. Cemented carbide is often used with brazing in other tool steels. The melting point of most brazing material is lower than the Alphas-V process temperature(1025C/1880F), therefore this brazing material might be melted and the insert might fall off after this process.
Make sure not to have any edge on the joint between the flat and R. Tangent point of R to the flat surface must be smoothly extended, otherwise seizure, abrasion, or a rough surface will occur. We strongly suggest not leaving the shape line below R. You could possibly extend your die life dramatically.
If the substrate hardness is insufficient and the substrate material shows plastic deformation, Alphas-V (TD) will more than likely have small cracks on the surface and it will not help you to extend the tool life. In this case, it is obvious that the die needs more hardness. If additional hardness is needed, what is the best material hardness? Is a harder substrate always better in order to obtain longer die life or are there any limits to get better result? If the damage is only existing on the die's surface, the hardness might not be the issue. On the other hand, if the damage is penetrated into the substrate, the hardness is likely the issue. The die life may be extended with harder substrate if the damage is caused by simply material fatigue. Furthermore, die life can be extended with lower hardness if the damage is caused by elasticity, thus it can't be answered properly what hardness would be the best. It will all depend upon each application.
Since the thickness of Alphas-V doesn’t effect its mechanical property, there shouldn't be any destruction of the coating as long as the coating is within 15-20 μm (0.0006” 0.0008”).
US Kondo would recommend the Alphas-V process on any sheet metal thicker than 2mm, HSLA material, dual phase material, or stainless sheet metal forming which has stronger adhesion and higher abrasive resistance under more severe application. Also the size of die, die material and shape are important factors and must be considered.
TD (Alphas-V) was world patented technology which was developed in Toyota Central Research & Development Labs led by Dr. Toru Arai. The Alphas-V(TD) process makes it possible to easily obtain the “Pure Carbide Layer” with ease, which is fine and comparatively thicker to other coatings and most importantly has extreme adhesion to the substrate material. Considering these properties, Alphas-V produces longer life, especially under severe condition.
Steel has been used by mankind since the Iron Age and has continued to improve along with the evolution of industry. Industrialists found that harder carbide particles contained in the substrate material's structure, facilitate better abrasive resistance properties. As a result of this information, “High Speed Material” was developed in the late 19’s century. High speed material contains only 20% carbide and innovative "Power High Speed Material", introduced 40 years ago, contain a maximum of 30% carbide. Furthermore “Tungsten Carbide (WC)” made it possible for steel to contain 80-90% carbide, but on the other hand, it had poor machinablity and becomes very brittle, which restricts the usage. Most recently, a super hard thin coating was developed and introduced called TD. TD has superior property to WC and 100% of carbide and nitride or other ceramic substances. TD is an innovative coating which has benefitted industry greatly.
Currently Chrome Plating, Surface Heat Treatment such as carburize , nitride, or plasma spray coating, or super hard thin coating such as TRD, CVD, and PVD are popular coatings in wide use. When your application is severe and needs high wear resistance properties, Alphas-V(TD) should be considered because Chrome Plating and Surface Heat Treatment would not be sufficient against extreme conditions. Plasma spray could be coated thicker than others, therefore it could be used even after some damage occur as long as there is no quality issue on the products. Generally, PVD has less distortion with a lower process temperature, but it's definitely inferior to Alphas-V(TD) or CVD in the point of adhesion strength thickness. It's not recommended for applications with extreme severe condition. TRD is scientifically similar to CVD, therefore the decision between the two should be made based upon application.
TRD coating (also known as TD-Toyota Diffusion) was developed in 1970 and began to make it practicable in the Japanese Automobile Industry. In the early 70’s, it was introduced to Asia, Europe and finally to the U.S.A. in the late 80’s. It has been widely used and contributed to the various industries around the world.
Alphas-V coating improves Wear Resistance, Corrosion Resistance, and Oxidation Resistance (Selection of carbide layer might be necessary for oxidation resistance), etc. It may also help improve the mechanical property of the substrate material if it is controlled by the surface quality such as Fatigue Strength or Heat Check.
Wear depends upon the usage conditions. There is plentiful test data published concerning general abrasive conditions, but it's almost impossible to know how the surface will be worn over the actual die surface in production. In Japan, a unique scientific society has been eagerly researching the phenomenon of surface abrasion or evaluation of the substrate material (called” Process Tribology”) under the practical industrial conditions. There are a number of research papers and comments available.
Alphas-V(TD) shows its superior wear resistance against Scratching, Sticking, Seizure, Fletching, Corroding, and Oxidizing abrasion because the coating is the carbide formed finely and strongly over the substrate material and is not only extremely hard, but also chemically stable. Regarding a high speed cutter among the cutting tools, the deterioration or reaction between the work material and tool steel causes the failure, therefore CVD or PVD is recommended since they contain less reactive properties compared with carbide and bring you better improvement.
This question can't simply be explained since there are various reasons for corrosion and oxidation. The carbide structure is chemically stable and tough against a wide range of corrosive atmospheres. Alphas-V is also generally superior to any other corrosive protections. Regarding anti-oxidation, Alphas-V will not be damaged under 800-900℉ temperature in the air.
Rubber sticking in rubber forming application or aluminum sticking in Aluminum Die Casting can be minimized with the Alphas-V coating.
a). Calo Tester- making wear mark over the substrate b). β Scope – Using β ray distraction strength c). X ray analysis d). Microscopic method over the coated section – Microscope and polishing devise(Required not to have round edge on the section, otherwise accurate number will not be measured)
There is no method to measure the adhesion strength. The scratch test with the critical loading is often used, however there is a big question about this method since there no plastic deformation of material involved and the peeling with continuous loading should consider to be “Fatigue Peeling” not “ Adhesion Strength”. Considering the mechanism of VC forming, it is obvious that Alphas-V(TD) has exceptional adhesion strength and has been proven with a number of supporting application data.
The thin layer (Alphas-V) bonding is very tightly reinforced with the hardened substrate material and will not break up like other carbide substances. Also, large residual stress contained in the carbide prevent the substrate surface from cracking or breaking, so that the static bending strength, impact strength and fatigue strength is enhanced with this process.
a).General consumable tools in production, such as Dies, Jigs, Fixtures, Blades etc. b).Machined parts requiring a high level of performance – Resistance against abrasion from contacting to metal, rubber, plastic, glass, ceramics, mineral and even non metal material like vegetation.
Many people misunderstand that Alphas-V (TD) would not be effective in a hot environment because VC starts oxidized significantly from 1020℉. This however is not the case in the real production world. In the case of Hot Forging applications, the work material is heated up to 1800℉(1000℃), however the actual temperature of a die in use is below 1020℉(550℃). If the die did heat up to over 1020℉(550℃), it would be for a very short time. Even though the temperature is over 1020℉, the TRD might be see some oxidization, but will give excellent abrasion resistance to the die surface to extend the life. You ultimately should see some benefit in the end. This could be same to cutting process of hot steel, melted glass, or aluminum injection mold. It would be rather important to prevent oxidation from the die by the inappropriate temperature, time , preheating in the air.
Yes, you can, as the matter of fact, there are many precedents for this application. Alphas-V (TD) contributes to improve the performance of razor blades used for cutting paper, plastic film, textiles, and rubber sheets. Please contact us if you are interested in this application because there are some important issue which need to be considered first, such as material selection, shape, post treatment etc.
Alphas-V is effective for use on a cutting blade in cutting application of 1” dia. steel or bigger and rotary forging dies. Alphas-V(Vanadium Carbide) is reinforced with the substrate material and has great impact resistance.
Yes, you will always have good results from this coating as long as it is used properly. The carbide(VC) coated by the Alphas-V process is far superior to any tool steel, therefore if you have not seen significant improvement (10-100 times), you might want to review the design, process, or material (Process Engineering) first and see if there is anything which has been inappropriately done prior to the coating. It is easy to conclude the coating failed, however it will not solve your real problem. It is critical to find the root cause of the die's failure by using the Process Engineering Capability and it is the only way to lead you to success. US Kondo is proud to have a wealth of knowledge and experience in Process Engineering Capability in many field, and are glad to share our knowledge with our customers.
Surface roughness, radius' are all true and smooth, material hardness, thickness of VC coating, and distortion are the 5 critical points for great results.
There is the possibility of a large distortion or warp which could cause fatigue destruction because of the bending stress.
The heating and cooling process of the material always progresses from outside to inside, therefore there is always temperature difference between the two. The Heat Expansive phenomenon, causes the deformation of the substance and heat stress. There is also always some changes in the micro-structure caused by the temperature (called Phase transformation and this is how the steel is hardened). The cubic content is changed with the different Phase, which causes dimensional changes and the timing of transformation between starting and ending will be different because of the temperature gap on outside and inside, which also be another cause for distortion. It would be impossible to eliminate ( 原理上ひずみ )all distortion and deformation, however it can be minimized.
Yes, it can be controlled and solved to a satisfactory level, however there are many factors (from die design to the end) related to distortion that happen prior to our process. If those aspects are well controlled and managed, distortion will be minimized, if not, distortion gets even larger. Please contact us and discuss what kinds of factors you need to consider.
The TD processed standard punch has been produced with ±5 um tolerance and sold without any final machining for the past 20 years. U.S. Kondo has been successful controlling a Dia. of 50-80mm punches within a ±10um tolerance.
Selecting the right material, which has more stability, is the most important quality to help reduce distortion. How the steel is cut from the stock will also help reduce distortion. The steel should be cut out of the stock vertically with the larger tolerance side up. Minimization of inconsistencies of heat treatment should also be considered. These are issues US Kondo can’t control, but it is definitely the 1st step to reduce the risk of distortion.
If the substrate needs to be hardened, air quenching steel will minimize the distortion since it can be hardened with a slow quenching speed. Steel with smaller carbide particles will minimize the distortion as well. Therefore, cold tool steel with both of these properties will minimize the chance of distortion. Cemented carbide will have the least distortion since it doesn’t have any phase transformation. If you have any further questions regarding steel distortion, please contact us.
Yes, but some side affects might occur after the distortion adjustment is made, such as loosing hardness etc. Distortion correction between 0.01mm – 0.5mm (larger pc has more distortion) has been done at U.S. Kondo. If you have concerns, please contact us.
US Kondo has created a “state of the art” control data program for collecting all of your die's dimensions for before and after the coating process. U.S. Kondo is working hard to create a distortion control database by analyzing collected data and applying it to our coating process. By using our program, we are able to provide the utmost reliable pre-coating dimensions to our customers. There is no cost for dimension change analysis, so please feel free to contact us.