Why does the saw blade crack?
Dora Zhang
2022-06-21 12:05:31
The crack of diamond saw blade, in fact, the usual welding stress can also cause similar cracks.
Cause analysis of crack in diamond saw blade
In some cases, the cracks on cemented carbide cutting tools are caused by excessive welding stress, which exceeds the strength of cemented carbide cutting tools. When welding the cutter, the height HC of the cutter body shall be 3 times greater than the height htof the blade. For example, HC is easy to cause fracture of alloy blade after welding; If hc<3, the surface layer of cemented carbide will produce tensile stress and crack easily; When hc=4 ~ 5, there is no significant stress on the cemented carbide surface, so it is not easy to produce cracks, even if there are cracks, it is not obvious; When hc<8, uniform load will be generated on the welding layer. However, the bending of the alloy blade produces tensile stress along the thickness direction of the alloy blade, and the force distribution in the welding layer is more complex than that of the alloy itself, because it is not bonded on one face, but on two, three or four faces.
The reason is that when the cemented carbide is rapidly heated and cooled, significant transient stress may be generated due to uneven heat distribution. During rapid heating, the outer layer of the cemented carbide is under compressive stress, and the middle is under tensile stress. When the allowable heating rate is exceeded, cracks or internal invisible cracks may appear. When welding cemented carbide tools, rapid cooling is also very dangerous. In this case, tensile stress will appear on the outer layer, causing cracks in the alloy.
Cause analysis of crack in diamond saw blade
In some cases, the cracks on cemented carbide cutting tools are caused by excessive welding stress, which exceeds the strength of cemented carbide cutting tools. When welding the cutter, the height HC of the cutter body shall be 3 times greater than the height htof the blade. For example, HC is easy to cause fracture of alloy blade after welding; If hc<3, the surface layer of cemented carbide will produce tensile stress and crack easily; When hc=4 ~ 5, there is no significant stress on the cemented carbide surface, so it is not easy to produce cracks, even if there are cracks, it is not obvious; When hc<8, uniform load will be generated on the welding layer. However, the bending of the alloy blade produces tensile stress along the thickness direction of the alloy blade, and the force distribution in the welding layer is more complex than that of the alloy itself, because it is not bonded on one face, but on two, three or four faces.
The reason is that when the cemented carbide is rapidly heated and cooled, significant transient stress may be generated due to uneven heat distribution. During rapid heating, the outer layer of the cemented carbide is under compressive stress, and the middle is under tensile stress. When the allowable heating rate is exceeded, cracks or internal invisible cracks may appear. When welding cemented carbide tools, rapid cooling is also very dangerous. In this case, tensile stress will appear on the outer layer, causing cracks in the alloy.
