The stability ofthe diamond segment is very important. The most direct performance is that ifthe segment is not stable, when the segment is cut, the sharpness will be fastand slow. Such a segment will not only cut the stone. , And will greatly damagethe machine, so the biggest quality problem of the diamond segment must be thestability of the product. So what factors determine the stability of theproduct? The main reason is the porosity of the diamond segment. So what isvoid ratio? How to calculate the void ratio? In what range of void ratios is agood segment (stable segment)? How does the void ratio ensure numericalbalance? Let's take a closer look:
Porosity refersto the actual volume occupied by the voids in a certain piled volume ofmaterial. Simply put, it is the volume of a segment divided by the volume ofthe powder and diamond by 1 minus the volume of the segment, multiplied by apercentage. The formula is as follows:
P'is theporosity, V0' is the total volume of diamond and powder, and V is the volume ofthe diamond segment.
So why can theporosity determine the quality of the segment? The porosity determines thecontent of diamond and metal materials per unit volume. The more the materialcomposition, the smaller the porosity and the higher the density, which canensure the cutting life of the segment to a certain extent. The porosity isalso a good judgment of the sintering pressure. When the sintering pressure isreasonable, the porosity can be maintained in a predictable and constant range.Such a segment is not only guaranteed in cutting life, but also in cuttingefficiency. Can maintain a constant speed.
What is theporosity to ensure the stability of the diamond segment? In fact, this value isnot constant, mainly because the diamond segment faces different cuttingobjects, and the material changes are extremely large. In addition, the diamondparticle size and concentration changes, and the matrix powder formula changes,resulting in no one. The specific value determines the stability of the diamondsegment. But it is foreseeable that if the porosity of each segment is within adesign range and the value does not change much, then the porosity of such a segmentcan reflect the quality of the segment, that is to say, the quality of thesegment can be judged by the porosity, not by the numerical value, but by thebatch sampling test results.
So how to ensureuniform porosity? The finished segment needs to pass the chemical compositiontest before it can be tested for product stability. Since non professionalorganizations cannot complete the composition test, in fact, the uniform voidratio test is still in the theoretical test stage. However, the uniformity ofthe porosity must be related to the following processes:
First, during the mixing process, whetherthe mixing is uniform (whether there is a problem with the mixing time, themixing range, etc.), whether there is a long-term mode and the diamond segmentpowder precipitates.
Second, there is a large weight differenceduring the cold pressing process.
Third, the pressure fluctuates during thehot pressing process.
Fourth, the temperature deviation occursduring the sintering process.
In general, the porosity of the diamond segmentcan reflect the stability of the product to a certain extent, and can alsoensure the yield of the product, but it is not a very economical measurementmethod.