HPDC Molds

Steel Grades

Steel Grade & Specification

Steel Grade

Specification

Hot work tool steel

JIS SKD61, AISI H11, H13, DIN 1.2367 etc.

Cool work tool steel​

IS SKD11, AISI D3, DIN 1.2379 etc.

High-Speed tool steel

JIS SKH52, AISI M2, DIN 1.3343 etc.

Powder Metallurgy High-Speed Steel

IS HAP40, AISI M4PM, DIN 1.3247PM etc.

Stainless Steel

JIS SUS304, SUS420, AISI 304, 420, DIN 1.4301, 1.4021 etc.

Alloy Structural Steel

JIS SNCM439, AISI 4340, DIN 1.6582 etc.

Failure Mode Analysis

Failure Mode Analysis of High Pressure Die Casting (HPDC) Molds

Item 1

Thermal Fatigue cracking

Causes

  • Repeated heating and cooling of the mold surface.

  • Thermal fatigue tensile stress generation.

  • Grain boundary degradation due to high-temperature oxidation.

  • Crack propagation due to tip effect.

  • Reduction in Cr content due to high temperature.

  • Decrease in mold hardness at high temperatures.

Countermeasures

  • Control of die casting conditions.

  • Management of mold surface temperature.

  • Selection of steel with high toughness.

  • Heat treatment ensuring high toughness.

  • Low-hardness diffusion-type nitriding treatment.

  • Control of mold release agent spray volume.

Countermeasures

  • Mold cooling design.

  • Steel material.

  • Heat treatment.

  • Die casting process.

  • Diffusion-type Nitriding treatment.

  • Selection and use of mold release agents.

Item 2

Seizure / Scuffing

Causes

  • Friction Between High-Temperature Molten Aluminum and Hot Mold.

Countermeasures

  • Lower mold temperature.

  • Reduce aluminum melt temperature.

  • Apply surface treatments (nitriding or coating).

Countermeasures

  • Mold cooling design.

  • Mold melt flow path design.

  • Aluminum melt temperature control.

  • Surface treatment.

Item 3

Erosion

Causes

  • Physical Friction Between High-Speed Aluminum Flow and Mold Steel.

Countermeasures

  • Reduce aluminum temperature and flow speed.

  • Apply surface treatments (coatings).

Countermeasures

  • Mold shape design.

  • Surface treatment.

Item 4

Corrosion

（Aluminum alloy wheel low mold）

Causes

  • Chemical Intermetallic Compound Formation Between High-Temperature Aluminum Melt and Mold Steel.

Countermeasures

  • Nitriding treatment.

Countermeasures

  • Mold cooling design.

  • Nitriding treatment.

Item 5

Cavitation

Causes

  • The air inside the mold cavity cannot be promptly expelled due to the high-speed flow of the aluminum melt. As a result, it becomes highly compressed, generating localized high temperatures that cause oxidation at the grain boundaries on the surface of the contacting tool steel, leading to grain boundary peeling.

Countermeasures

  • Change the flow direction of the melt.

  • Reduce the flow speed of the aluminum melt.

Countermeasures

  • Mold design.

  • Flow simulation analysis of the aluminum melt.

Item 6

Wear

Causes

  • Uneven Thermal Expansion and Friction Between Core, Cavity, and Slide Due to Heating.

Countermeasures

  • Mold cooling design.

  • Nitriding treatment (with different hardness settings).

Countermeasures

  • Mold design.

  • Nitriding treatment.