Secondary Technical Expert and Senior Engineer of AVIC Shenyang Liming Aero Engine (Group) Co., Ltd. Shen Zhiyun
With the rapid advancement of aero-engine technology, the manufacturing processes for critical components have seen significant improvements. At the same time, opportunities for collaboration with international aerospace companies have expanded greatly. Through subcontracted part production, we’ve gained deeper insights into the manufacturing procedures and technical documentation used by foreign firms. It’s clear that the main differences between China and advanced aviation manufacturing countries lie in several key areas.
First, the design requirements for parts are more comprehensive abroad. They include detailed specifications on machining points, surface tolerances, and corner radii. For example, the position, direction, and depth of NC machining points must be clearly defined, as shown in Figure 1. Additionally, there are strict regulations on the flatness and roundness of weak-rigid parts, ensuring they meet assembly standards. The chamfering and rounding of edges also require precise measurements, avoiding sharp corners that could cause stress concentration issues.
Second, the quality of raw materials is more consistent in foreign suppliers. Subcontracted parts often use refined blanks that are heat-treated and inspected using ultrasonic methods. This results in stable material properties and reduces the need for additional processing steps. In contrast, our domestic materials still require extra treatments like stress relief and non-destructive testing, increasing the production cycle.
Third, technical standards are more complete abroad. There are well-defined guidelines for quality control, engineering drawings, and tolerance specifications. Special standards exist for critical components such as discs, covering surface finish, hole finishing, and edge treatment. However, in China, such standards are less developed, and many aspects rely only on dimensional tolerances without specific process instructions.
Fourth, the process procedures in foreign manufacturing are highly detailed. From fixture installation to tool path planning, each step is clearly outlined, making it easier for operators to follow. This level of detail improves consistency and reduces reliance on individual skill levels. In China, the procedures tend to be simpler, leaving more room for interpretation and variability.
Fifth, process control is stricter overseas. Every characteristic dimension and tooling structure is carefully specified, ensuring product stability. In contrast, Chinese process control focuses mainly on dimensional checks, with less attention to surface integrity and
Other critical factors.
Lastly, the tooling used in foreign subcontracting is more efficient. Fixtures are lightweight, made from non-metallic or aluminum materials, and designed for interchangeability. High-precision measuring devices and advanced cutting tools further enhance accuracy and efficiency. In China, the tooling is often heavier, less flexible, and uses lower-precision measuring instruments.
By analyzing these gaps, it becomes clear that China's aero-engine industry needs to adopt better design concepts, learn from global best practices, and improve the manufacturing of key components through collaboration. This will not only boost technological development but also bring economic benefits, leading to a win-win outcome for all stakeholders.
Hand Shower
kaiping aida sanitary ware technology co.,ltd , https://www.kpaidafaucets.com