At present, the metal powder forming and the traditional metal plastic processing technology are relatively close, so for a specific metal powder part, after confirming the steel mold pressing method, the relevant technical requirements and the original Data, including part drawings of the parts, powder composition and process performance, processing flow, pressing methods, and batch size, are used for the design of compacts and dry powder pressing dies.
Then, before the design work, it is necessary to understand the relevant parameter requirements. First of all, we need to calculate according to the technological characteristics and material performance parameters of the metal powder and the compaction. Usually in the formulation of metal powder press molding process and dry powder pressing mold design, the metal powder process characteristics and material performance parameters include: 1, powder bulk density, that is, the average density of the metal powder in the mold before pressing; The compressibility is determined according to experimental data or relevant standards; 3. The degree of deformation of powder can be determined according to experimental data or relevant standards; 4. Powder flow stress.
In addition, these parameters need to be known when designing dry powder pressing molds: 1. the density of a given powder compact; 2. the amount of spring back of the parts after pressing (and subsequent plastic forming); 3. the sintering of the parts After the line shrinkage; 4, sintering oxidation or other causes of the amount of quality loss; 5, subsequent plastic processing caused by the increase in the density of parts.
After these parameters are determined, the next step is to determine the appropriate press forming method. That is to say, after mastering the above data and data, the form of the dry powder pressing mold and the corresponding pressing method should be selected according to the actual production conditions, and the pressing direction should be selected.
The next step is to calculate the dry compaction of the pressed compact. In the process of calculation, the volume, quality and relevant dimensions of the compacts should be determined according to the processed powder parts to determine the size of the concave mold cavity of the dry powder compaction die and to verify the dimensional accuracy of the compacts.