Categories

Cracks and Tears in Metal Casting: Causes and Prevention

Understanding Metal Casting Cracks

Cracks in metal casting can happen from multiple reasons, including brittleness, impurities, and shrinkage. Understanding the causes of cracks in metal casting is crucial for maintaining casting quality and reducing defects and rejects

Types of Metal Casting Cracks and Their Causes

1. Hot Cracks
Hot cracks, one of the most common issues, form when metal cools too quickly, especially when it’s still partially molten. Rapid cooling creates stress during solidification, resulting in cracks. Protech Transfer machines prevent hot cracks in castings by providing precise temperature control and reducing the risk of cooling related cracks.

2. Brittleness-Related Cracks

When materials are hard or brittle,  due to impurities, oxides or improper alloy composition, cracks are more likely to form. Alloy-specific solutions for crack-free casting are crucial. High-precision casting machines from Protech Transfer ensure the proper mixing of alloys in the protective atmosphere while melting, which ensures their homogeneity and significantly lowering brittleness-related fractures, oxides and impurities.

3. Shrinkage 

Shrinkage, a result of cavity formation during the cooling phase, can weaken the material and lead to cracks. Protech Transfer’s casting solutions, which offer controlled cooling rates to ensure a solid final product help reducing brittleness in metal casting, can minimize this issue.


Identifying and Testing Metal Casting Cracks

Classifying cracks can involve simple tests, like bending items to check for brittleness. For a more detailed analysis, alloy-specific solutions for crack-free casting involve metallographic analysis with tools like Scanning Electron Microscopes (SEMs), which analyze defect types and help to improve casting processes.


Preventing Hot Cracks in Metal Casting

Proper temperature management is key to avoiding hot cracks, especially with metals like silver. Here are essential tips on how to prevent hot cracks in casting:

  • Control Flask Cooling: Allow flasks to cool in place for at least 4 minutes before quenching to reduce risk of hot cracks. Protech Transfer’s advanced cooling systems provide equipment for reducing brittleness in metal casting, making it easy to prevent common cooling issues.
  • Redesign Sprue Systems: Redesigning sprue systems can reduce thermal stress, one of the main contributors to hot cracking. Machines from Protech Transfer offer adjustable parameters for optimized metal flow, reducing brittleness-related cracks and hot crack risks.

Material-Specific Casting Solutions

Some metals, such as palladium, are more prone to hot cracks due to factors like silicon, carbon and hydrogen contamination. Protech Transfer’s machines from Indutherm.de support the use of specialized alloys and offer alloy-specific solutions for crack-free casting, making them ideal for high-quality palladium work.


BEST MACHINERY – BEST SERVICE
Sales Hotline: +66 8 6332 9347
LINE ID Sales: @pttsales
24/7 Service Hotline: +66 8 9227 9154
LINE ID Service Support: @pttsupport
See all machines

Protech Transfer Co., Ltd. (Main Office)

189 Soi Chockchaijongjamlearn, Rama 3 Rd.,
Kwang Bangpongpang, Khet Yannawa,
Bangkok 10120, Thailand (view map)

Protech Transfer Co., Ltd. (Showroom)

119 Soi Chockchaijongjamlearn, Rama 3 Rd.,
Kwang Bangpongpang, Khet Yannawa,
Bangkok 10120, Thailand (view map)

PTT sales and service
Website maintenance by: dp