WHAT ARE BREAKAGES OF METAL DIES? – CAUSES OF CRACKING, GALLING, WEARING

Breakages of metal dies are; “fracture” which occurs when the die material separates into pieces during a forming process, “galling” which occurs when the pressure (load) around a contacting part of the die and workpiece increases, causing abnormal friction, “wear” which occurs when the dies are repeatedly used for production, gradually changing their shapes, and so on.

In this article, we will introduce some types of breakages of metal dies, their causes, and their solutions.

TYPES OF BREAKAGES OF METAL DIES AND CAUSES

Breakages of metal dies occur during forming processes for some reasons, changing their designed shapes.

Fractures, galling, wear, crack, and chipping are considered to be breakages of dies:

• Fracture: the state where the part of, or whole material of the die separates into pieces
• Galling: the state where part of the die surface is worn out or fallen off
• Wear: the state where the shape of the die is gradually changed by friction
• Crack: the state where the cracks originating from abnormal layers occur on the die
• Chipping: the state where part of the die is missing

We will explain the causes of each breakage, as well as the solution and case study below.

CAUSES OF FRACTURE AND SOLUTIONS

Fracture is the state where the die’s part of, or whole material separates into pieces.

Reducing produced stress during forming, changing the material to one that has high toughness, reviewing and changing the structure of the die (interface), and changing the surface treatment are considered to improve the situation.

We offer solutions; identifying the causes of the crack by inspecting (with the microscope, or by cutting) actual dies, reviewing and changing the structure of the die with CAE (including utilizing containers by STRECON), and changing the layout (process, and shape).

We also have experiences such as preventing a large number of defective products leaving from the factories, with our Bolt Piezoelectric Load Sensor “PiezoBolts” to monitor the change in forming pressure, and to detect abnormal amplitude when a fracture occurs.

For more detailed information, please click the link below.

WHAT IS FRACTURE? – CAUSES AND SOLUTIONS

CAUSES OF GALLING AND SOLUTIONS

Galling is the state where part of the die surface is worn out or fallen off (and mostly stretched) when seizures occur, and the high-hardness pieces where between the upper and the lower die, or on the sliding surface between the die and the material, scrape the metal off.

Adding surface treatments (coating, and nitriding), modifying the asperities on the die surface, improving the hardness of the die, reviewing and changing the clearance between the die components, and optimizing the lubricating treatment of the workpiece to improve the state.

We offer solutions; checking the actual dies, changing the coating treatment, changing the finishing process of the die surface, and improving the production conditions including lubricate treatment.

We also have experiences such as supporting clients to optimize appropriate lubricant conditions by measuring how the knockout load changes by the conditions of lubricate treatments with Bolt Piezoelectric Load Sensor “PiezoBolts”.

For more detailed information, please click the link below.

WHAT IS GALLING? – CAUSES AMD SOLUTIONS

CAUSES OF WEAR AND SOLUTIONS

Wear is the state where the shape of the die has gradually changed by the friction of the die and material during the forming process.

Reviewing and changing the lubricants, modifying the asperities on the die surface, and changing material and surface treatments can improve this state.

We also have experiences such as measuring the difference in the peak load between new and worn-out dies before reaching the limit with our Piezoelectric Load Sensor “PiezoBolts” to monitor and prevent defective products.

WHAT IS TOOL WEAR? – CASE STUDY OF WEAR VISUALIZATION WITH LOAD SENSOR

CAUSES OF CRACK AND SOLUTIONS

Crack is the state where the cracks originating from abnormal layers such as amorphous layers caused by the rapid temperature change in the topmost surface of the die, and affected layers caused by electrical discharge machining, occur on the die.

Reviewing and changing the process of forming dies to stabilize the internal quality of the surface layer, changing to materials with higher toughness, and managing heat through the forming processes are expected to improve the state.

WHAT IS CRACK? – CASE STUDY OF DETECTING SMALL CRACKS WITH LOAD SENSOR

CAUSES OF CHIPPING AND SOLUTIONS

Chipping is the state where part of the die is missing because the stress was temporary beyond the proof stress during a forming process.

Stabilizing the friction state of the die by uniformizing the lubricant, and preventing tiny foreign objects through the forming process.

We have experiences such as measuring slight differences in the load between usual, and when chipping occurs with our Piezoelectric Load Sensor “PiezoBolts”. The clients could stop the line when something happened, and prevent defective products.

WHAT IS CHIPPING? – CAUSES AND SOLUTIONS WITH LOAD SENSOR

CONCLUSION

Hope you enjoyed this article.

We will offer our support to prevent metal die by utilizing CAE and sensing technology with the load sensor.

If you have any issues such as producing defective products due to breakages of the dies, and thinking of preventing die breakages earlier…please contact us.