Sand casting is a metal forming process in which a sand mold is first created. Molten metal is poured into the mold cavity for solidification. The sand shell is subsequently removed after the metal components have cooled and formed. Some sand casting components require a secondary machining process after casting to improve product accuracy.

Sand casting can process a wide range of metals and alloys, including iron. Sand casting is a cost-effective and efficient technology, which is generally flexible with regard to size and change of geometry. A quality casting is deemed fit for its designated use or purpose, at the most economical level. Maintaining high-quality levels requires quality control methods at all points in the casting process. This article looks at the types of quality control methods that are used for sand casting parts.

When are Quality Control Methods Used for Sand Casting Parts?

There are several stages in the sand casting process when quality control methods are utilized:

• Raw materials: Before the sand casting process even begins, it is important to inspect the raw materials, to ensure they meet the designated quality standards.
• Sand molds: The sand mold is inspected to make sure it is capable of withstanding the casting process and producing the desired component.
• Finished castings: After melting, pouring, heat treatment, secondary machining, and surface treatment, the final castings are inspected for finish and accuracy, to ensure they meet the customer specifications.

What Type of Quality Control Methods are Used for Sand Casting Parts?

The following types of quality control methods can be used to ensure high quality throughout the sand casting process:

• Visual Inspections: Quality control experts use visual techniques that look for any cracking, tearing, distortion, holes, or voids in the casting.
• Metallurgical and Mechanical Properties Inspection: A metallurgy lab at the foundry is used to test chemical composition and alloy property analysis. Mechanical quality control methods confirm that the metal meets the specified requirements for hardness, tensile strength, yield strength, and load-bearing capability. This may include hardness testing, using the Brinell hardness test or Rockwell hardness test, tensile, and impact testing. Service load testing may be performed to evaluate the casting’s ability to bear a specified load.
• Dimension Inspections: Casting Industry Standards and customer specifications set a range of values casting dimensions can fall within. Dimensions can be verified using micrometers, thread and plug gauges, and height gauges. Dimensional inspection equipment includes CMMs, interferometers, vision systems, optical comparators, profilometers, portable CMM arms (contact and non-contact), and laser scanners.
• Destructive Testing: This may include chemical analysis, elevated temperature tension testing, stress rupture testing, corrosion testing, hardness testing, and failure analysis.
• Non-Destructive Testing (NDT): Non-destructive testing assesses the internal and surface quality of a casting, without destroying it. This may include X-ray inspection to verify internal integrity, magnetic particle testing, ultrasonic testing, fluorescent penetration inspection, hydrostatic pressure testing to verify the performance capability of fluid-filled parts to identify leaks, and magnetic particle inspection.

Learn More About Types of Quality Control Methods Used for Sand Casting Parts

Impro is among the global Top 5 sand casting companies for complex high-performance iron sand castings, according to Roland Berger’s 2019 Report. We are a global, integrated manufacturer of high-precision, high-complexity, and mission-critical components for diversified markets. We use state-of-the-art process technologies and equipment throughout our manufacturing operations. If you are interested in finding more information about sand casting and our process capabilities, please contact our team of experts today.