BAM friction apparatus

Determination of friction sensitivity is applicable to solids, pastes, and gel-type substances. To determine the friction sensitivity, a thin sample is placed under a load between two roughened surfaces, and the surfaces are then rubbed together in a controlled manner. The load can be varied. Results from this action, such as smoke, cracking, or discoloration, are observed. Examples of apparatus of this type are the BAM friction apparatus, shown in Figure 2.30, the rotary friction test, and the ABL friction test. 

FIGURE 2.30. The BAM Friction Apparatus Horizontal and Vertical Cross-Sections... 

BAM friction apparatus or Julius Peters friction apparatus The BAM method is an improved method and is reported to yield reproducible results. This apparatus is used extensively in Europe [67]. It consists of a rough porcelain plate which is rigidly attached to the sliding carriage of the friction apparatus. 

The testing procedure using the BAM Friction Apparatus is described below. 

Table 2.7. The dependence of the normal force between the porcelain plate and the pistil upon the mass of the weight and its position on the loading atm in the BAM Friction Apparatus...

The BAM Friction Sensitivity Apparatus is shown in Figure 2.11. The operation mode of the apparatus is as follows. Friction is created electromechanically between the cylindrical porcelain pistil and the plate bearing the sample. The pistil and the plate are of definite roughness. The size and the shape of the plate and the pistil are shown in Figure 2.12. 

Figure 2.11. BAM friction sensitivity apparatus (JULIUS PETERS KG, Berlin, Germany)...

There are two versions of the friction test apparatus in operation, a standard size apparatus and a small size version. The small device is particularly designed to test sensitive materials such as primary explosives. It can be operated with different weights on the porcelain bolt holder allowing loads in the range of 0.1 to 10 N. On the standard BAM friction test apparatus higher forces on the pin varying from 5 to 360 N can be applied. 

Figure 13 BAM friction test apparatus (left) and scheme of the measuring principle (right)...

Table 9.1 Impact (drop-hammer machine, 2.5 kg hammer, 50 % probability) and friction sensitivity (BAM apparatus, 1 event in 10 trials) of powdered CP [6]...

---