Cleanliness Testing of Die-Cast Parts: A Critical Step in Quality Inspection

Cleanliness testing of die casting parts is designed to verify whether the cleaning of die-cast parts has been adequately performed and whether their cleanliness meets international and industry standards. If you are interested in learning more about cleanliness testing for die-cast parts, please read the article below.

What Is Cleanliness Testing for Die-cast Parts?

Cleanliness refers to the degree of contamination of a part by impurities. From production to transportation, die-cast parts are highly susceptible to contamination. The cleanliness of a die-cast part indicates the extent to which it is contaminated by impurities.

The cleanliness test for die-cast parts involves cleaning the components and then analyzing the impurity particles in the cleaning solution to generate a corresponding cleanliness report. This report documents key parameters such as the mass, size, and quantity of impurity particles present in the solution.

Why Is Cleanliness Testing so Important for Die-cast Parts?

You might wonder why cleanliness testing is so crucial for die-cast components. Contaminants can negatively impact both the performance and service life of these parts. Moreover, many industries have specific cleanliness standards for their components.

Contamination of Die-cast Parts Can Cause Severe Losses

Contamination on die-cast parts primarily consists of particulate matter and corrosive chemical contaminants.

Particulate contamination primarily originates from post-processing stages, such as grit left behind from shot blasting or sandblasting, or chips generated during machining. These residual particles can cause wear, operational issues, noise, and even failures when the die-cast parts are assembled into equipment, posing safety hazards for production and usage.

Chemical contamination primarily stems from residual release agents within die-casting molds or leftover cutting fluids from machining processes. The most significant issue caused by chemical contamination is that it makes die-cast parts more susceptible to corrosion. Once corrosion occurs, the mechanical strength of the die-cast parts is greatly reduced, and their service life is significantly shortened.

Additionally, contamination can occur during transportation due to environmental factors, such as fine particles and non-volatile residues (NVR).

Industry-Specific Standards

In industries with significant demand for die-cast components—such as automotive, medical, marine, and electronics—specific industry standards govern part requirements. These standards encompass not only precision and mechanical strength specifications but also cleanliness requirements for die-cast parts.

Take the automotive industry as an example: standards like ISO 16232 and VDA 19.1 specify cleanliness requirements. Similarly, the healthcare industry also has specific international industry standards. If you intend to die-cast automotive components or parts for medical devices, cleanliness testing becomes an essential step in product quality inspection.

What Is the Process for Cleanliness Testing of Die-cast Parts?

The cleanliness testing of die-cast parts can be divided into the following four steps: cleaning, filtering, drying, and visual inspection. The following content will provide a detailed explanation of the key points for each step.

Step 1: Cleaning

Common cleaning methods include ultrasonic cleaning and pressure washing. For die-cast parts with simple shapes that require cleaning both inside and out—typically small to medium-sized components—we usually opt for ultrasonic cleaning. For die-cast parts with complex geometries, we employ pressure washing. This method utilizes nozzles of various shapes and high-pressure cleaning guns to ensure thorough cleaning.

Common cleaning methods include ultrasonic cleaning and pressure washing. For die-cast parts with simple shapes that require cleaning both inside and out, we typically recommend ultrasonic cleaning. For parts with complex geometries, we employ pressure washing, utilizing various nozzle shapes and high-pressure washers to ensure thorough cleaning.

At this stage, you should focus on selecting the appropriate cleaning solution for your die-cast parts. For the most common aluminum or zinc alloy parts, neutral or mildly alkaline water-based cleaning solutions containing surfactants are the most suitable and widely used. Of course, if your die-cast parts have specific cleanliness requirements, mildly alkaline cleaning solutions can also be selected as needed.

Step 2: Filter and Dry

Thoroughly filter the cleaning solution used to clean the die-cast parts using a filter membrane. Dry the filter membrane and collect the contaminants from its surface.

Step 3: Visual Inspection

Examine the sample under a microscope with illumination. Determine the particle size of the particulate contamination and count the number of particles to obtain the solid particle contamination results for the tested object’s components.

Conclusion

Overall, cleanliness testing of die-cast parts is a critical step in quality inspection. If your die-cast parts require high cleanliness standards, contact Sunrise. We will conduct cleanliness testing to ensure your die-cast parts meet industry standards.