Understanding the causes of these problems and applying proper solutions can help improve product consistency and cutting performance.
1. Diamond Segment Dimensions Do Not Meet Requirements
Incorrect segment dimensions are one of the common problems during production. In most cases, this issue is related to improper hot pressing parameters or incorrect mold selection.
The main causes include:
-nsufficient pressing pressure during the sintering process;
-Low sintering temperature;
-Short holding time for pressure or temperature;
-Incorrect graphite mold size.
When the pressure is insufficient or the sintering conditions are not properly controlled, the segment cannot be fully compacted, resulting in excessive height or dimensional deviation. Incorrect mold specifications may also cause the finished segment to become too high or too low.
To prevent this problem, manufacturers need to accurately control hot pressing parameters, including temperature, pressure, and holding time. During material loading, operators should also carefully check graphite molds to avoid using incorrect molds, which may cause the segments to fail quality inspection and become unsuitable for secondary sintering.
2. Insufficient Density or Incorrect Hardness
The density and hardness of diamond segments directly influence cutting performance and service life. If these properties are not within the proper range, the saw blade may experience poor cutting efficiency, excessive wear, or even segment damage during operation.
This problem is usually caused by improper hot pressing process settings, such as:
-Incorrect sintering temperature;
-Improper holding time;
-Unsuitable pressure parameters.
For existing formulas, manufacturers can optimize production based on proven hot pressing parameters. For newly developed diamond segment formulas, theoretical parameters should be tested and adjusted according to the actual results of the first production batch.
Through continuous adjustment and testing, the optimal sintering process can be established to achieve the required balance between hardness, wear resistance, and cutting performance.
3. Insufficient Diamond Segment Strength
Low segment strength is another important quality issue that may affect tool safety and cutting stability.
Generally, there are two main reasons:
(1) Impurities During Mixing or Filling Process
During powder mixing or mold filling, foreign materials such as graphite particles or other contaminants may accidentally enter the mixture. These impurities can weaken the internal structure of the segment and reduce its mechanical strength.
To avoid this issue, raw materials must be properly stored, screened, and handled during the entire production process.
(2) Improper Formula Design or Sintering Process
Another possible reason is an unsuitable diamond segment formula or incorrect sintering process. This may result in:
-Low strength of the working layer;
-Weak transition layer strength;
-Poor bonding between the working layer and transition layer.
When the bonding strength between these layers is insufficient, the segment may break at the connection area during cutting or when being welded onto the saw blade.
Improving the Bonding Strength Between Working Layer and Transition Layer
In traditional diamond segment production, the working layer and transition layer often use similar material formulas. However, to reduce manufacturing costs, many saw blade segments use economical iron-based alloys without cobalt in the working layer.
For the transition layer, a certain amount of cobalt may be added to improve welding strength between the segment and the steel core. However, different material compositions can create differences in thermal expansion coefficients.
During cooling after sintering, these differences may generate residual shrinkage stress between the working layer and transition layer, reducing the overall strength of the segment.
To solve this problem, manufacturers should:
Ensure all metal powders and additives are clean and free from contamination;
Carefully design the composition of the working layer and transition layer;
Select materials with similar thermal expansion characteristics when different formulas are required.
A properly designed transition layer helps improve welding reliability, reduce internal stress, and achieve better cutting performance.
