Common Problems and Cause Analysis of Hard Alloy Pressing
Hard alloy is an alloy material made from hard compounds of refractory metals and bonded metals through powder metallurgy process, with high hardness, wear resistance, good strength and toughness. Due to its unique performance, it is often used to make rock drilling tools, mining tools, drilling tools, measuring tools, and so on. It is widely used in fields such as oil and gas, chemical industry, engineering machinery, and fluid control. Hard alloy is a material made by pressing through powder metallurgy process
1. Layered
Most layering starts from the edges and extends into the billet. The reason for the layering of the compression block is the elastic internal stress or elastic tension in the compression block. For example, the cobalt content of the mixture is relatively low, the carbide hardness is high, the powder or particles are finer, the forming agent is too few or unevenly distributed, the mixture is too wet or too dry, the pressing pressure is too large, the single weight is too large, the shape of the pressing block is complex, the mold smoothness is too poor, and the table surface is uneven, all of which may cause layering.
2. Cracks
The phenomenon of irregular local fracture in the compressed block is called cracking. Due to the tensile stress inside the compression block being greater than the tensile strength of the compression block. The tensile stress inside the compression block comes from the elastic internal stress. The factors that affect delamination also affect cracks. The following measures can be taken to reduce the occurrence of cracks: extending the holding time or multiple pressurizations, reducing pressure, single weight, improving mold design and appropriately increasing mold thickness, accelerating demolding speed, increasing forming agents, and increasing material loose density.