ASTM B975-18 pdf free.Standard Test Method for Measurement of Internal Stress of Metallic Coatings by Split Strip Evaluation (Deposit Stress Analyzer Method).
1.1 This test method for determining the internal tensile or compressive stress in applied coatings is quantitative. It is applicable to metallic layers that are applied by the processes of electroplating or chemical deposition that exhibit internal tensile or compressive stress values from 2(X) to 145 (XX) psi (1.38 to 10(X) MPa).
1.2 The values stated in either SI units or inch-pound units arc to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore. to ensure conformance with the standard, each system shall he used independently of the other, and values from the two systems shall not be combined.
1.3 This standard doe’s no! purport to addres.v all of the safety concerns, if anv associated i’ith its use. it is the responsibility of the user of ibis standard to establish apprrpriau’ safetv health, and e,,rirrmmenial practices and determine the apphcahiliiv of irgulaiorv lunitation.s prior to use.
1.4 This iniernatiimal standard ‘as developed in accordance with internationally recogni:ed principles on standardization established in the Decision on Principles for the Dc i’dopnu’nt of International Standards. Guides and Recoin,nt’ndaiions issued by the’ World Trade Organ izatiol, Technical Barriers go Trade (TBT) Committee.
3. lerminology
3.1 Definitions of Ter,ns Specific to This Standard:
3.1.1 average deposit thickness, n—average deposit thickness equals the deposit weight in grams divided by the specific gravity of the deposit in graiiis per cubic centimetre multiplied by the plated deposit surface area per test strip (see Eq 3).
3.1.2 constant K. n—this certifiable calibrated number is determined experimentally for each material lot of lest strips manufactured to enable %imple mathematical calculation of the inernal deposit stress while factoring the influence of the percent elongation difference between the deposit and the substrate without the use of complicated bent strip formulas. See Note 4 in Section X.
3.1.3 helix, n—metal strip approximately 0.01 to 0.013 in. (0.025 to 0.033 cm) thick formed as a helix approximately 0.9 in. (2.3 cm) in diameter and 6.1 in. (15.5 cm) long with or without a polytetratluoroethylene WfFE) coating on the inside surface.
3.1.4 in-site dei’ke. n—this device holds a test strip during the application of a coating.
3.1 .4.1 Discussion—Anodes are located external to the sped men holder.
3. 1 .5 iniernil stress, n—stress in a given layer of coating can result from foreign atoms or materials in the layer that stress the natural structure of the deposit as the coating is being formed from sources independent of foreign atoms such as misfit dislocations and the result of additional processing.
3. 1 .5.1 Discussion—Stress that develops in a given layer of material is measured as pounds per square inch or megapascals where I MPa = 145 psi.
3. 1 .6 mea.suring stand, n—this stand supports the test strip above a logarithmic scale that enables determination of the total number of increments spread between the test strip leg tips.
3.1.7 modulus of elasticity, n—stress required to produce unit strain. sshich may be a change in length (Young’s modulus), a twist of shear (modulus of rigidity or mwiulus of torsion), or a change in volume (hulk modulus).
3.1.8 power suppfr n—rec(ilier to supply amperage for plating.
3.1 .9 self-contained plating cell, n—this cell contains two anodes within the cell at an equal distance from the test strip that are suspended in electrolyte for deposition to occur. A section for a heating coil and a pump for solution agitation is an option.
3.1.10 lest strip. ti—metal strip formed from (lal stock that receives the coating of material being evaluated for internal stress.ASTM B975 pdf free download.