Physical and mechanical tests

The external characters (colour and appearance of the surface and section) are examined and determinations made of the specific gravity, strength and permeability as for bark-tanned leather. 

The analysis of chromed leather comprises the following determinations- 

—As in tanned leather, but with a smaller quantity of substance. The result obtained does not give the true proportion of mineral matter, since the acids combined with the chromium and aluminium oxides axe eliminated during calcination. 

Qualitative analysis of the ash will reveal any addition of extraneous mineral substances (weighting). 

In 100 c.c. of this solution the chromic acid is reduced by prolonged boiling with hydrochloric add and a little alcohol, chromium and aluminium hydroxides being then precipitated by means of ammonia and the precipitate weighed (CrtO + A120 ) in the usual way. 

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R. H. Mark, Handbook of Physical and Mechanical Testing of Paper and Paperboard, Marcel Dekker, Inc., New York. 

Upon completion of the preliminary evaluation of design and materials, any required revisions are made. The next step is to fabricate several hundred parts from the material which performed most satisfactorily during the initial evaluation. These parts will be subjected to many types of physical and mechanical tests in the laboratory. Parts are also installed in automobiles at the G.M. Proving Grounds and fleet cars to obtain actual field experience. 

Chemical, Physical, and Mechanical Tests. Manufactured friction materials are characterized by various chemical, physical, and mechanical tests in addition to friction and wear testing. The chemical tests include thermogravimetric analysis (tga), differential thermal analysis (dta), pyrolysis gas chromatography (pgc), acetone extraction, liquid chromatography (lc), infrared analysis (ir), and x-ray or scanning electron microscope (sem) analysis. Physical and mechanical tests determine properties such as thermal conductivity, specific heat, tensile or flexural strength, and hardness. Much attention has been placed on noise /vibration characterization. The use of modal analysis and damping measurements has increased (see Noise POLLUTION AND ABATEMENT). 

The complete and systematic examination of leather, including physical and mechanical tests 1 and chemical analysis, is carried out principally for tannin- or chrome-tanned leathers. The methods to be used in this examination arc given below and are preceded by the procedure to be followed in sampling. 

In order to identify the strength characteristics of the obtained mixtures were conducted physical and mechanical tests in a laboratory tensile machine PM-10 (Table 1 of Section 5.6, Fig. 1 of Section 5.6). Testing, training and payment module samples were assayed according to GOST 9550-81. 

Proposed Method of Test for Plane Strain Fracture Toughness of Metallic Materials, ASTM Standards on Physical and Mechanical Testing of Metals Nondestructive Test. Part 31, ASTM International, West Conshohocken, PA, May 1969, pp. 1099-1114. 

ASTM Book of Standards, Part 31 Physical and Mechanical Testing of Metals (1969). 

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