Detection of cracks and bonding defects
in disk brake linings.
盤式制動襯片的粘接和裂紋缺陷的檢測
In our Application Reports 06/97 and 07/97, we reported on ultrasonic testing of brake linings and of bonded joints in brake bodies.
在應用報告06/97 和07/97中，我們講述了在制動體中粘接接頭和制動襯片的超聲檢測
The present case deals with testing of brake bodies, consisting of a steel base plate, a welded-on grid mat as bonding agent and the sinter-fused braking substance (friction lining),
下圖展示一個焊接上的網格墊作為粘接劑，鋼基體和燒結熔融的制動物質組成的制動體檢測。
SOLUTION:方案
The present brake lining structure with its extremely high sound absorption and scattering calls for the through-transmission technique using a test frequency of 100 kHz. We recommend the use of the probes type B 0,1 NN for this application case. This probe type enables a dry and point-to-point coupling.
由于制動襯片結構具有很高的聲吸收和散射，因此需要頻率為100khz的穿透法技術，推薦使用B0型1 NN 探頭，這種探頭類型能夠實現干式和點對點耦合。
In order to ensure uniform coupling conditions, it is necessary to have a device enabling to reach a pressure force of ~100 N.
為了確保耦合的均勻，需要一個能夠達到100N壓力的設備
In the case of cracks and bonding defects, a low through-transmission amplitude is obtained due to the reduced acoustic transmittance. On the other hand, a high sound amplitude indicates a flaw-free area.
有裂紋和粘接缺陷的存在情況下，由于降低了聲能的穿透性能，穿透技術得到的波幅會很低，另一方面，在沒有缺陷的區域穿透技術得到的聲波波幅會很高。
The following figure is an example of the distribution of the through-transmission amplitude (in % screen height) over the lining surface, obtained by point scanning.
下圖是通過點掃，在襯面上獲得穿透法波幅高度（示波屏高度百分比）分布的舉例
SUITABLE EQUIPMENT:
設備
Ultrasonic flaw detectors: USM 22L USD 10NF
超聲儀器
Probe: B 0,1 NN (transmitter and receiver)
探頭