ISO 18558-2015 pdf free download

ISO 18558-2015 pdf free download.Fine ceramics (advanced ceramics, advanced technical ceramics) — Test method for determining elastic modulus and bending strength of ceramic tube and rings
Céramiques techniques — Méthode d’essai pour la determination du module élastique et de Ia résistance en flexion des tubes et anneaux en céramique.
I: Tubes property: no further surface preparation for evaluating the mechanical properties of existing ceramic tubes or rings, including as-fired, surface polished, or surface machined tubes.
Cut the ceramic tube into several rings according to the size requirement in Zi. Then grind and polish the cutting section faces of the ring to a parallelism of 0,02 mm or better. Clean the test pieces with alcohol or pure water, etc. The edges of the test pieces shall be chamfered to avoid edge damage for strength tests. Chamfering is not important for the tests of elastic modulus. Then a slot width about 0,2 r is cut by using a cutting machine for ceramics.
II: Material property: test piece is machined from tubes or bulk ceramics, surface shall be ground and polished before cutting into rings.
For a given ceramic tube, if surface treatment is in need, the grinding and polishing shall be performed parallel to the tangent direction of the tube first. Cut the ceramic tube into several rings according to the size requirement in 7]. And then, grind and polish the cutting section faces of the ring to a parallelism of 0,02 mm or better. Clean the test pieces with alcohol or pure water, etc. The edges of the test pieces shall be chamfered to avoid edge damage for strength tests. Chamfering is not important for the tests of elastic modulus. Then a slot width about 0,2 r is cut by using a cutting machine for ceramics.
NOTE The aim of polishing is to minimize the damage created in the test pieces due to the preparation process.
6.2.2 Test piece storage
The test pieces shall be handled with care to avoid the introduction of damage after test piece preparation. Test pieces shall be stored separately and not allowed to impact or scratch each other.
6.2.3 Number of test pieces
A minimum of 6 test pieces is required for the tests. For a more detailed statistical analysis of the
strength (e.g. Weibull analysis), at least 30 pieces are recommended.
7 Test procedures
7.1 Testing machine and loading speed
Use universal niechanical testing machine with a crosshead speed of 0,1 mm/mm for the elastic modulus tests and 0,5 mm/mm for the strength tests, respectively. The test piece shall contact well with the supporting and loading anvils.
NOTE Suitable loading rate actually depends on the ring size, the test can be performed by position or load control so that the time to failure wIll be between 10 s to 60 s for the split ring test piece.ISO 18558-2015 pdf free download.