Chinese standard GB/T54-94 aluminum alloy die castings
Chinese standard GB/T54-94 focuses on the quality requirements and inspection specifications for aluminum alloy die-castings. It is a key technical document guiding the production and quality control of aluminum alloy die-castings. This standard applies to all aluminum alloy products produced using the die-casting process. It provides comprehensive and detailed regulations covering aspects such as dimensional accuracy, surface quality, and internal quality. It aims to ensure that aluminum alloy die-castings meet the various performance and usage requirements of practical applications, providing strong technical support for the healthy development of related industries.
Dimensional accuracy is one of the fundamental requirements for aluminum alloy die-castings in GB/T54-94. The standard specifies corresponding dimensional tolerance grades and allowable dimensional deviation ranges based on the different uses and structural characteristics of die-castings. This is because aluminum alloy die-castings must precisely mate with other components during assembly. Inadequate dimensional accuracy can lead to assembly difficulties and even affect the performance of the entire equipment. For example, the bearing holes in the gearbox housing in an automotive transmission require extremely high dimensional accuracy. Excessive dimensional deviation can lead to loose bearing installation, affecting the transmission efficiency and service life of the transmission. Therefore, manufacturers must ensure that the dimensional accuracy of die-castings meets standard requirements through precise mold design, strict process control, and accurate measurement methods.
Surface quality is another important aspect that GB/T54-94 focuses on. The standard clearly defines the surface roughness and surface defects (such as pores, shrinkage, cracks, cold shuts, etc.) of aluminum alloy die-castings. Good surface quality not only improves the appearance quality of die-castings, but also enhances their corrosion resistance and wear resistance. Excessive surface roughness will easily cause dirt to accumulate on the surface of die-castings, affecting their performance and aesthetics; while defects such as pores and cracks on the surface will seriously reduce the mechanical properties and sealing of die-castings, and may cause safety accidents in harsh environments such as high pressure and high temperature. In order to ensure the surface quality of die-castings, the standard stipulates corresponding inspection methods, such as visual inspection, gaging measurement, non-destructive testing, etc. Manufacturers need to strictly inspect die-castings according to these methods and eliminate unqualified products.
Internal quality is a key factor in ensuring the long-term stable operation of aluminum alloy die-castings, and GB/T54-94 also has strict regulations on this. The standard requires that aluminum alloy die-castings must not have defects that affect their performance, such as severe shrinkage cavities, looseness, inclusions, etc. Although these internal defects are difficult to detect during visual inspection, they will significantly reduce the strength, toughness, and sealing of the die-casting. During use, they may cause problems such as breakage or leakage due to uneven force. To verify the internal quality of die-castings, the standard recommends the use of non-destructive testing methods such as radiographic testing and ultrasonic testing. These methods can effectively detect tiny defects within die-castings and ensure product quality. At the same time, the standard also clearly stipulates the permissible degree of internal defects and establishes different acceptance levels based on the importance of the die-casting and the conditions of use.
In addition to the aforementioned provisions, GB/T54-94 also stipulates the labeling, packaging, transportation, and storage of aluminum alloy die-castings. Proper labeling facilitates traceability and management of die-castings, clarifying information such as product model, specification, and production batch. Appropriate packaging prevents damage during transportation and ensures product integrity. Standardized storage conditions prevent quality changes caused by environmental factors (such as humidity, high temperature, and corrosion). While seemingly minor, these regulations are crucial for ensuring consistent quality of aluminum alloy die- castings from production to use. Strict implementation of GB/T54-94 will improve the overall quality of aluminum alloy die-castings and promote the standardization and regularization of the aluminum alloy die-casting industry.
