ISO 6474-1:2019 pdf free
ISO 6474-1:2019 pdf free.Implants for surgery一Ceramic materials
Specimens shall be produced equivalent to the regular production of the implants. The same feedstock,comparable shaping technology (e.g. axial pressing, isostatic pressing), high temperature process (e.g. sintering, hot isostatic pressing) and hard machining (e.g. grinding, polishing) shall be applied. The shaping of specimens shall be accomplished according to the requirements of the test.
The manufacturer shall declare and justify whether the production of the specimens can be assessed as equivalent to the regular production.Finished products or portions of them can be used for the evaluation of material properties.However, due to geometric restrictions and the risk of damage during specimen preparation, it is not recommended to produce specimens as portions of finished products for evaluation of the following material properties:
a) strength (see 6.4);
b) fracture toughness (see 6.6);
c) cyclic fatigue (see 6.9)
For selection, preparation and evaluation of the specimen, the following guidelines shall be followed:
a) the wall thickness of the selected specimens shall represent maximum and minimum of the manufacturer’s products;
b) the position of the micrographs shall represent regions at the centre and at the skin of the selected specimens;
c) the specimen selection shall reflect the possibility of temperature deviation in the furnace;
d) using regular products as specimens for microstructure evaluation is recommended; if other specimens are used, they shall be produced equivalent to the normal manufacturing of the products;
e) the requirement for linear intercept grain size given in Table 1 shall be matched at each selected position of the micrographs;
f) the standard deviation of the linear intercept grain size shall be determined from the data of all selected micrographs; the standard deviation shall match the requirement given in Table 1.
The determination of linear intercept grain size shall be organized such that homogeneity of the regular production can be assessed to a sufficient statistical relevance. The manufacturer shall justify the organization of grain size determination for his specific manufacturing process. It is recommended that the manufacturer analyse the reliability, repeatability and maintenance of the manufacturing process with respect to microstructure (e.g. validation) and utilize these data for the organization of the regular production control. If this detailed analysis is accomplished successfully, the regular production control of the microstructure can be performed with a reduced number of specimens and micrographs.ISO 6474-1 pdf free download.
