Detection of cracks and bonding defects
in disk brake linings.
盤(pán)式制動(dòng)襯片的粘接和裂紋缺陷的檢測(cè)

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(yīng)用報(bào)告06/97 和07/97中，我們講述了在制動(dòng)體中粘接接頭和制動(dòng)襯片的超聲檢測(cè)
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(gè)焊接上的網(wǎng)格墊作為粘接劑，鋼基體和燒結(jié)熔融的制動(dòng)物質(zhì)組成的制動(dòng)體檢測(cè)。

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(dòng)襯片結(jié)構(gòu)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(shù)，推薦使用B0型1 NN 探頭，這種探頭類(lèi)型能夠?qū)崿F(xiàn)干式和點(diǎn)對(duì)點(diǎn)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(gè)能夠達(dá)到100N壓力的設(shè)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(shù)得到的波幅會(huì)很低，另一方面，在沒(méi)有缺陷的區(qū)域穿透技術(shù)得到的聲波波幅會(huì)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(guò)點(diǎn)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(shè)備

Ultrasonic flaw detectors: USM 22L  USD 10NF
超聲儀器
Probe:     B 0,1 NN  (transmitter and receiver)
探頭