SU63257A1 - Method for testing abrasive materials - Google Patents

Description

Of the methods characterizing the physical properties of abrasive materials, still only lime, which consists in the abrasion of a small amount of abrasive grit between glass discs and in determining the amount of glass removed by abrasive from one of the disks, after a certain number of turns. In this method, the disks make complex planetary movements of each other. Since such a movement of grain can easily fly out from under the disk, only small nominal grains can be subjected to the test (in the main way L1 80). For the same reason, only very small amounts of abrasive grit (on the order of .50 mg) are used for each experiment. At the same time, a very small amount of glass is removed from the disk weighed before and after the experiment. These conditions, which are essential for this, well-known method, greatly limit its use and are sources of a number of errors that affect the accuracy of the test results.

A distinctive feature of the pre-larae Moro method of testing abrasive materials. In a grain there is an abrasion of the mother-ala between two plates, one of them or both of which are reciprocated relative to each other. After a certain number of reciprocating movements, the percentage ratio of the crushed part of the grains to the whole is determined; circle, taken for the experience. This is the number of character. It is the strength of the grain during its abrasive work.

In this method, the test grain is prepared by carefully screening the screens on two sieves, the first of which has a mini: the size of the holes through which the grain of the test number still passes, and the second - the next in order number - with a smaller value the holes through which we test the cruise during the crash, does not pass. For example, the grit 20 is sifted onto the sieve No. 20 and 24, the grit L 24 through the sieve L 24 and 36, etc.

After such sowing, the grains, freeing themselves from larger and smaller fractions, have a very constant grain size, which is a necessary condition for obtaining positive results of the experiment.

From the grain prepared in this way, either the sample or the no. of a certain numerical grain size, or iBi in the form of a certain amount of grains in weight (it is rational to take the number of cores. 1-2 g). To take a certain numerical quantity: grain1 is recommended by fourfold preliminary experiments: B1 put on an analytical balance a weight, for example, 100: grains, and then wai technical scales to weigh samples for experiments that correspond to a certain numerical quantity of grains within 1-2 g. So, for grains about 24 it is rational to scrim the amount of grain corresponding to the weight of 5000 grains, for KpyniKtH No. 36 - respectively 9000 grains, for No. 46-18000 pieces, etc.

The weighed amount of grain is poured onto one of the plates, - on it, another plate (having a certain weight) is laid, and the latter is brought manually or mechanically into a uniform reciprocating motion.

After performing a certain number of reciprocating movements, they are sifted cleanly onto the hourly glass HI screened on a sieve, on which it remained at preliminary sieving. Both the fine and the coarse fractions are reclaimed and the ratio of the grinded grains to the whole grains taken for the experiment is calculated by percentage. This value characterizes the strength of the grain during its work.

In order to obtain reproducible results, all conditions of experience must be strictly standardized with respect to the size of the grain; (yes Nn obtained for grains with

different grain size, incomparable with each other), the weight of the sample is taken or the number of grains taken, the speed of movement of the plates, the number of slides, the weight of the plates. as well as material; plates So for example, on. Based on the work done, the following rational conditions of experience can be recommended, yielding repeatable results with minimal results.

1.Materialplity - mgka steel with a hardness of Brunet / 105.

2. The weight of the upper plate together with the LOBOLNITELNYI load-m - 1.25 kg.

3. Working surface of the top plate 120 X 80 mm.

4. The sliding surface of the plate is -220 mm. path length - 100 mm.

5. Manual movement of the slab without any lift and additional pressing at a smooth and uniform pace.

6. The number of sun-translational movements of the upper plate 40 with a fixed lower plate.

7.Speed of movement should be such that forty-four speeds are not less than in 75 seconds.

8. For each test material, EXPERIMENT psvto.r is four times and sets the average value of the results of four experiments, taken as the result of the test.

Subject invention

A method of testing abrasive materials, characterized in that a sample of grains of a certain size is abraded under a given pressure between the reciprocating d.Vision panels and: about the quality of the abrasive. Materia.cha is judged by the degree of grinding of the sample.