Hard shell effect caused by the internal-external temperature difference during sintering of large blanks

The surface of a large blank is over-sintered while the core is under-sintered, forming a hard shell wrapping a soft core. This problem is relatively common in sintering molding production and needs to be comprehensively analyzed and solved from multiple aspects of material, process, and equipment.

(1) Process factor: Heat conduction of large products is slow; this factor affects the '2079851475616104453 and final quality of the product. (2) Temperature parameter aspect: During heating, the surface reaches the sintering temperature first and shrinks, sealing the internal gas and heat; temperature deviations directly affect the physical and chemical state of the material and the reaction process. (3) Material aspect: Fluctuations in raw material performance indicators or insufficient pretreatment affect molding quality. (4) Process aspect: Deviations in the control of key process parameters cause the '2079851475616104453 to deviate from optimal conditions. (5) Equipment aspect: Equipment accuracy and maintenance status affect the stable execution of process parameters.

(1) Implementation measure: Use an extremely slow heating rate (e.g., <20℃/h) to ensure temperature balance between inside and outside, formulate specific operation plans in combination with actual production conditions, and verify the implementation effect. (2) Material selection: Use auxiliary preheating and multi-stage temperature control, establish material selection evaluation standards, and determine the optimal plan through comparative tests. (3) Implementation measure: Manufacture in separate parts and then weld., formulate specific operation plans in combination with actual production conditions, and verify the implementation effect. (4) Preventive measure: Establish a sound process control standard and quality inspection system, and regularly review process data for continuous optimization.

This problem needs to be comprehensively analyzed from multiple dimensions of material, process, equipment, and operation, and solved by systematically optimizing process parameters and the quality control system.