ISO 14188:2012 金属およびその他の無機コーティング—遮熱コーティングの熱サイクル抵抗および熱衝撃抵抗を測定するための試験方法 | ページ 2

Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.

International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.

The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights.

ISO 14188 was prepared by Technical Committee ISO/TC 107, Metallic and other inorganic coatings.

Introduction

Thermal barrier coatings are highly advanced material systems, generally applied to surfaces of hot-section parts made of nickel or cobalt based superalloys, such as blades, vanes and combustors in gas turbines and aero-engines, operated at elevated temperatures.

The purpose of these coatings is to insulate metallic components for an extended period at elevated temperatures by employing thermally insulating materials which can sustain an appreciable temperature difference between load bearing alloys and coating surfaces. By shielding these parts, these coatings permit the use of high operating temperatures by restricting exposure of structural parts to these temperatures, thereby extending their lives.

This International Standard specifies test methods, applicable to these thermal barrier coatings, for measuring thermal cycle resistance and thermal shock resistance using appropriate heating and cooling procedures.

1 Scope

This International Standard specifies test methods applicable to thermal barrier coatings for measuring thermal cycle resistance by using steady cyclical heating and cooling procedures, and for measuring thermal shock resistance using a heating and quenching technique.

These measurements are used for the evaluation of durability of thermal barrier coatings to thermal strain.

This International Standard is applicable for screening thermal barrier coating systems including materials and processing, and not for controlling the thermal spraying processes.

2 Normative references

The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

3 Terms and definitions

For the purposes of this document, the following terms and definitions apply.

3.1

thermal barrier coating

TBC

two-layer coating consisting of a metallic bond coat and an oxide top coat, in order to reduce heat transfer from outside the top coat through the coating to the base material

Note 1 to entry: When a TBC is exposed to operating at a high temperature, thermally grown oxide (TGO) develops on the top of the bond coat. The substrate is a typically heat-resistant high nickel based alloy class, UNS N 06002 type of material. The coatings, illustrated in Figure 1, are applied by using physical or chemical vapour deposition or by thermal spray processes, such as plasma spray and high velocity oxy-fuel (HVOF) spray conforming to ISO 14232.

Figure 1 — Diagrammatic view of the section and effects of TBC

Key

1	combustion gas temperature
2	top coat
3	TGO
4	bond coat
5	thermal barrier effect
6	temperature
7	TBC
8	cooling air temperature
9	substrate

Bibliography