Die casting mold sticking commonly presents the following four issues:

1. Mold Structure Design Issues

The design of the draft angle for the finished product is particularly crucial in both the product's exterior design and the mold structure design, as it directly affects the success of the die-casting process. If the draft angle is too small after the product cools and shrinks, or if there is a reverse draft angle in the design, it can cause the product to stick to the mold, leaving residual material inside the mold cavity. Over time, this residual material erodes the mold surface. Additionally, if the surface roughness of the mold cavity is poor and not smooth, it can cause aluminum liquid to stick to the mold, further affecting the mold's lifespan.  

Solution: Adjust the draft angle of the finished product to reduce mold drag, thereby naturally extending the mold's lifespan.

2. Physical Properties of Aluminum Elements

Aluminum has a strong affinity with iron, and the higher the temperature of the aluminum liquid and the mold, the more active the atomic reaction. Combined with high-speed injection pressure, this results in an increasingly large erosion area on the mold surface, reducing its strength and lifespan.  

Solution: Perform surface hardening treatment on the mold surface, such as nitriding (ensure the diffusion layer is not too thin) or coating with molybdenum (an alloy with elements that have a low affinity with aluminum).

3. Die Casting Parameter Issues  

In conventional die casting, the switch from low to high speed typically occurs when the low-speed plunger pushes the aluminum liquid to fill the shot sleeve. At this point, high-speed injection begins, atomizing the aluminum liquid into the mold cavity. This direct high-speed thermal shock to the mold core accelerates mold erosion, leading to sticking. If flash is not removed in time, it intensifies the bonding between the metal liquid and the mold, exacerbating mold sticking and significantly shortening the mold's lifespan.  

Solution: Use a multi-stage low-speed function on the die casting machine to avoid or mitigate high-speed thermal shock areas. If flashing is detected, remove it immediately and reduce the high-pressure injection speed.

4. Release Agent Quality and Spraying Issues

The quality of the release agent and its uniform application also directly impact the degree of mold sticking. When the release agent is atomized and sprayed onto the mold, it undergoes physical and chemical changes, forming an isolation layer between the mold and the aluminum liquid. This ensures that the product can be smoothly released after cooling and reduces production defects. Insufficient release agent can cause mold sticking, while excessive application can hinder the evaporation of the water base and increase gas within the mold cavity, leading to other defects.  

Solution: Improve the atomizing nozzle of the release agent to ensure uniform spraying. The release agent should have good emulsification effects to prevent buildup.

Fulltech Casting has extensive experience and professional problem-solving capabilities. If you have specific die casting needs, please contact Fulltech Casting. Our expert team will provide you with the highest quality service and support.