Views:2 Author:Site Editor Publish Time: 2020-07-02 Origin:Site
The degree of deformation is one of the main factors affecting the densification process of the TZM alloy slab, and it also ultimately affects the mechanical properties of the TZM alloy slab. When the TZM alloy plate is rolled, the degree of deformation of the material is expressed by the compression ratio. Compression rate refers to the reduction in loudness of the cross-sectional area of the TZM alloy plate. The amount of compression is divided into pass compression rate and total compression rate. The total compression rate and the pass compression rate have a great influence on the alloy mechanical properties of TZM alloy plates.
According to the experiment, the strength and elongation of the TZM alloy sheet after rolling increase with the increase of the total compression ratio. The mechanical properties of the TZM alloy sheet after rolling at different compression ratios are better than the rolling at small compression ratios in terms of tensile strength and elongation. This is because the large amount of deformation and the rapid deformation speed are not only conducive to the bridging of the sintering holes in the TZM alloy sheet blank produced by powder metallurgy, the grains are fully deformed and broken, but also the uniformity of the deformation structure of the blank along the cross-section is significantly improved. Internal defects are eliminated or reduced.
When the rolling pass compression rate is small, the deformation will mainly concentrate on the surface of the plate. From the surface to the inside, the amount of deformation gradually decreases, and the deformed tissue is unevenly distributed along the cross section. The deformation of the core grains is smaller than the grains of the surface layer due to the axial extension, which to a certain extent suppresses the improvement of plasticity.
The amount of deformation of the slab also has a certain effect on the density of the material. The density of TZM alloy increases rapidly as the amount of deformation increases. When the processing rate exceeds 60%, the density gradually approaches the theoretical value, which means that most of the grains begin to undergo plastic deformation. At this time, the sintered state began to transform to the processed state, and the properties of the slab also changed significantly, increasing the plastic deformation of the grain. With the elimination of voids, the transformation process of the sintered state to the densely processed state is completed, thereby increasing the density of the sintered blank to close to the theoretical value.
In addition, the hardness of the material also increases with the amount of deformation, and the change is very obvious. It can be seen that the amount of deformation has a great influence on the hardness of the material.