Die casting tooling typically the mold through which molten metal is injected during the die casting process. The tool is mainly composed of 2 equal parts, one being the cover die and the other the ejector die.
Now, the die tooling is used in several projects to produce high-volume metal parts, which is an advantage; however, the repeated use of the mold can affect the final product’s quality and durability.
In this blog post, we shed some light on factors that cause mold failure, tips on how to extend die-cast tooling life, and lastly, where to get the best engineers to design high-quality tooling life for your manufacturing process. Read on to learn More!
Factors That Cause Die Casting Mold Failure
Thermal Fatigue Cracking
Thermal fatigue failure is the most common cause of die casting failure, the reason being that most dies are usually exposed to thermal and mechanical loads, and the constant recycling and changes in temperature between the casting and lubricant applications stress the die casting surface, resulting in cracking. Most cracks occur as early as 2000 cycles and worsen as the cycles continue increasing.
Gross Cleavage Fracture
Now, after the cracking occurs on the die surface, the gross cleavage fracture starts to take over. Let’s get technical for a bit. As the cracking occurs on the die surface, it becomes difficult for the die material to resist the propagation of cracks under tensile stress. These stresses are usually a result of changing temperatures within the die casting body.
Erosion Damage
Erosion damage also occurs on the die surface but near the ingates, leading to the die casting cavity. Erosion mainly damages die casting metal by warning it away. This is usually caused by the cavitations produced by the collapse of gas bubbles when the molten metal enters the streams.
Corrosion and Chemical Attack
Corrosion and chemical attacks occur due to oxidation of the die surface by its environment. The oxide produces fill and causes pressure to the thermal fatigue cracks, thus weakening the steel die surfaces. However, if you want to extend the die cast tooling life, ensure that the die lubricant applied isn’t corrosive to the die material.
Tips for Improving Die Casting Tooling Life
Careful Selection of Mold Material
The mold material is more like the foundation of the manufacturing process. Thus, it’s important to take as much time as necessary to make the right decision. A high-quality die casting mold material should exhibit an excellent overall performance of hot work mold steel. This means that it should be able to withstand the high temperatures during the process.
At Sunrise Metals, we prolong the die cast tooling life by using high-quality steel that exhibits high wear and corrosion resistance. To top it off, our tool makers do some surface modifications to the die material. The result? High hardness, good wear resistance, and good anti-sticking performance.
Paying Attention to the Mold Design
Every aspect of the design affects the life of your die casting tooling.
Let’s start with the pouring system design. It’s usually the most crucial part of the design. If the size and position of the inner sprue are not right, you may experience erosion in the long run.
The forming parts designs resonate with the desired metal part that should be produced. You want to avoid sharp corners as they can stress the material, resulting in cracking.
Lastly, in the formwork design, you need to ensure that the mold has the appropriate thickness so that it doesn’t bend or deform during the casting process.
For high-quality and efficient designs, it’s best to get an engineer to design for you. This way, you will ensure that both the design and the end product are in good performance. Sunrise Metals has the best engineers with years of creating mold designs. We also have software that lets them know if the design is ready to go or if there are potential problems.
Heat Treatment of The Mold
One major cause for shorter die-cast tooling life is overheating.
The die casting process usually undergoes high pressure and temperature conditions. If the die material is not to the highest standards, it will wear off due to thermal and structural strength. Thankfully, there are heat treatment methods that make the mold heat-resistant.
A great example of the heat treatment method is the surface modification technique, which generally utilizes physical and chemical methods to change the surface properties of the mold and make it more hard and wear-resistant. Sunrise Metals has tool makers who are well aware of the heat treatment methods, including the conventional ones.
Make Use of Efficient Mold Cooling System
Utilizing a mold cooling system is yet another way of extending your die cast tooling life. As mentioned earlier, Thermal cracking usually occurs as a result of fluctuations in temperature. Using a mold cooling system can help avoid this.
Additionally, being keen on the die casting parameters keeps the temperature in control. For example, reduce the pouring temperature and the injection pressure, as they can cause corrosion. Also, shorten the high-temperature holding time to avoid stressing the die material.
Here is a bonus tip: Ensure you regularly check and clean the cooling system to ensure the cooling water is not blocked from maintaining a stable temperature.
Preheat The Mold
Preheating the mold is one way of avoiding the constant changes in temperatures which result in cracking. You see, when molten metal is poured into the mold, it usually results in an exchange of temperature. Why, you ask?
The die casting material itself has its own temperature, which is usually lower than that of the molten metal. If you preheat the mold, you are able to prepare the mold surface for high temperatures, thus avoiding the risk of reducing die cast tooling life through cracks.
Now, the method of preheating the mold depends on the mold design. If you have a complex design, heating the mold through a blowtorch or gas will serve you well. For simple designs, a slow press shot is the perfect way.
Maintenance of Signal Line
The signal line is crucial since it also affects the quality of the part. At no point should there be any contact of their signal line between the die casting machine and mold. This should be avoided if the mold has an inbuilt neutron flux measuring.
Short-circuiting usually happens when the signal line comes in contact with water or when there is a breakage of the contactor. As a result, the mold gets damaged since the short-circuiting causes alarms and automatic stoppages. To extend the die cast tooling life, you have to maintain the signal line.
Regular Tooling Care and Maintenance
Getting a qualified engineer to design a high-quality die-cast tool is only a step in the right direction. To extend your die-cast tooling life, you need to consider doing regular care and maintenance. Most aluminum die casting tools are built to withstand roughly 80,000 shots. Afterward, the tools start to experience gate erosion and core wear. However, with regular care and maintenance, you can get the most out of your tools.
At Sunrise Metals, we value quality and durability, which is why, when you invest in our die casting tools, you are assured that they will serve you more than the typical shots. Our tool makers do the care and the maintenance for you, ensuring the mold retains its properties when it is new. The best part? You don’t need to stress yourself about extra costs; once you buy the die casting tool from us, leave the rest to us- from designing to maintenance.
How to Make the Most From Your Die Cast Tool?
- Always make use of a high-quality die lubricant, as it will help to reduce friction and wear, thus extending the life of the die-cast tool and improving the quality of the castings.
- Make sure to control the pressure applied to the molten metal. The pressure applied to the molten metal must be within the recommended range to increase tooling life and performance.
- Ensure there are no casting defects, as they can weaken the cast tool and shorten its life.
- You should also allow for lenient tolerant zones on non-critical designs. This ensures you produce high-quality parts without compromising the durability of the die-cast.
Looking for a die casting tooling manufacturer in China? Don’t settle for less if you want to prolong your die-cast tooling life. Sunrise Metal is well known for producing high-quality die casting tools in China and other countries. With the expertise of our engineers, you can rest assured that you will acquire both quality and durability.
Contact us today and let us make the most out of your manufacturing project!