1、APPROVED FOR PUBLIC RELEASEDISTRIBUTION IS UNLIMITED NASA TECHNICAL HANDBOOK NASA-HDBK-6007A National Aeronautics and Space Administration Approved: 12-02-2013 Washington, DC 20546-0001 Superseding NASA-HDBK-6007 HANDBOOK FOR RECOMMENDED MATERIAL REMOVAL PROCESSES FOR ADVANCED CERAMIC TEST SPECIMENS
2、 AND COMPONENTS MEASUREMENT SYSTEM IDENTIFICATION: METRIC/SI Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NASA-HDBK-6007A APPROVED FOR PUBLIC RELEASEDISTRIBUTION IS UNLIMITED 2 of 22 DOCUMENT HISTORY LOG Status Document Revision Approval Date Desc
3、ription Baseline 11-19-2007 Initial Release Revision A 12-02-2013 General Revision Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NASA-HDBK-6007A APPROVED FOR PUBLIC RELEASEDISTRIBUTION IS UNLIMITED 3 of 22 FOREWORD This Handbook is published by the
4、 National Aeronautics and Space Administration (NASA) as a guidance document that provides engineering information; lessons learned; possible options to address technical issues; classification of similar items, materials, or processes; interpretative direction and techniques; and any other type of
5、guidance information that may help the Government or its contractors in the design, construction, selection, management, support, or operation of systems, products, processes, or services. This Handbook is approved for use by NASA Headquarters and NASA Centers, including Component Facilities. This H
6、andbook establishes guidelines and recommendations for machining of advanced ceramics. Machining of advanced ceramics is often necessary to achieve certain design requirements, such as dimensional (tolerance) requirements, geometric shape, functional fit, and surface finish. However, surface grindin
7、g can cause a significant decrease in the strength of advanced ceramics due to the introduction of surface flaws. The magnitude of the loss in strength is determined by the grinding conditions and the response of the material. The effect on strength of varying a single grinding parameter or several
8、grinding parameters can be measured and assessed; however, doing so can be both time consuming and expensive depending on geometry, application, and material. Often grinding procedures have been developed by experienced users for particular components or applications, but these procedures have not b
9、een compiled or presented in a generalized manner accessible to inexperienced users. Therefore, a need exists to compile and/or develop a set of geometry-based grinding procedures that inexperienced users of advanced ceramics can apply as a starting point in specification writing and fabrication of
10、ceramic test specimens and components. Requests for information, corrections, or additions to this Handbook should be submitted via “Feedback” in the NASA Standards and Technical Assistance Resource Tool at https:/standards.nasa.gov. Original Signed By: 12/02/2013 _ _ Michael G. Ryschkewitsch Approv
11、al Date NASA Chief Engineer Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NASA-HDBK-6007A APPROVED FOR PUBLIC RELEASEDISTRIBUTION IS UNLIMITED 4 of 22 SECTION TABLE OF CONTENTS PAGE DOCUMENT HISTORY LOG 2 FOREWORD . 3 TABLE OF CONTENTS . 4 LIST OF
12、FIGURES 5 LIST OF TABLES . 5 1. SCOPE . 6 1.1 Purpose 6 1.2 Applicability 6 2. APPLICABLE DOCUMENTS 7 2.1 General 7 2.2 Government Documents . 8 2.3 Non-Government Documents . 8 2.4 Order of Precedence 8 3. ACRONYMS AND DEFINITIONS 9 3.1 Acronyms 9 3.2 Definitions . 9 4. GUIDANCE . 10 4.1 Significan
13、ce and Use . 10 4.2 Interferences 10 4.3 Apparatus 11 4.4 Precautionary Statement 12 4.5 Recommended Procedures for Specific Configurations . 12 4.6 Post-Machining Treatments 16 5. ADDITIONAL GUIDANCE 17 5.1 Reference Documents . 17 5.2 Intended Use 17 5.3 Key Word Listing 17 APPENDICES A Recommende
14、d Polishing Specifications for Ceramic Windows 18 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NASA-HDBK-6007A APPROVED FOR PUBLIC RELEASEDISTRIBUTION IS UNLIMITED 5 of 22 LIST OF FIGURES FIGURE PAGE 1 Horizontal-Spindle Surface Grinding for Machi
15、ning Prismatic Uniaxial Flexure Bars .12 2 Vertical-Spindle Surface (Blanchard) Grinding and Polishing for Machining Biaxial Flexure Disks .13 3 Outside Diameter Cylindrical Grinding for Machining Cylindrical Tension/Compression Rods 15 LIST OF TABLES TABLE PAGE 1 Scratch/Dig Specification Details .
16、 22 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NASA-HDBK-6007A APPROVED FOR PUBLIC RELEASEDISTRIBUTION IS UNLIMITED 6 of 22 HANDBOOK FOR RECOMMENDED MATERIAL REMOVAL PROCESSES FOR ADVANCED CERAMIC TEST SPECIMENS AND COMPONENTS 1. SCOPE 1.1 Purpo
17、se The purpose of this Handbook is to cover recommended material removal processes (i.e., machining or grinding) for advanced ceramics. It is applicable to both test specimens and components, hereafter referred to as “specimens.” This Handbook is not intended to replace or supersede customary (e.g.,
18、 internally accepted or proprietary) or application-matched machining/grinding practices. Instead, it is intended to provide recommended material removal procedures developed from experience and testing, and thereby ensure consistent test specimen and component performance. Geometries addressed in t
19、his Handbook include prismatic sections, flat plates (disks and square plates), and cylindrical rods. Grinding parameters, including diamond (abrasive)-grit size and material removal rates, are addressed in addition to cutting fluid type and conditions. Appendix A, Recommended Polishing Specificatio
20、ns for Ceramic Windows, provides a specific application example. Fabrication of test specimens and components can introduce dimensional variations, subsurface damage, and residual stresses which may have pronounced effects on measured mechanical properties and behavior. Because universal or standard
21、ized procedures for surface preparation do not exist, guidance on specimen preparation is useful to ensure that such variations are minimized in determining material properties such as ultimate strength. The procedures described in this Handbook address some of the factors responsible for machining
22、effects. It should be understood that final machining steps may or may not negate machining damage introduced during the initial steps. Therefore, measures like surface roughness alone of the specimen may not be adequate for determining ultimate strengths of advanced ceramics. Specimen fabrication p
23、rocesses should be controlled and reported with the goal of minimizing subsurface damage. 1.2 Applicability This Handbook is applicable to material removal processes (machining or grinding) for advanced ceramics. It is applicable to both test specimens and components, which are referred to in this H
24、andbook as “specimens.” This Handbook is approved for use by NASA Headquarters and NASA Centers, including Component Facilities and Technical and Service Support Centers. This Handbook may also apply to the Jet Propulsion Laboratory or to other contractors, grant recipients, or parties to agreements
25、 only to the extent specified or referenced in their contracts, grants, or agreements. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NASA-HDBK-6007A APPROVED FOR PUBLIC RELEASEDISTRIBUTION IS UNLIMITED 7 of 22 This Handbook, or portions thereof, ma
26、y be referenced in contract, program, and other Agency documents for guidance. When this Handbook contains procedural or process requirements, they may be cited in contract, program, and other Agency documents for guidance. The practice of material removal (machining or grinding) for advanced cerami
27、cs may involve hazardous materials, operations, and equipment. This test method does not purport to address the safety problems associated with its use. It is the responsibility of the user of this practice to establish appropriate safety and health practices and determine the applicability of regul
28、atory limitations prior to use. This Handbook is intended primarily for use with advanced ceramics and optical materials that “macroscopically exhibit” isotropic, homogeneous, continuous behavior. While this practice is intended for use on monolithic advanced ceramics and optical materials, certain
29、whisker- or particle-reinforced composite ceramics as well as certain discontinuous fiber-reinforced composite ceramics may also meet these macroscopic behavior assumptions. Generally, continuous fiber ceramic composites (CFCCs) do not macroscopically exhibit isotropic, homogeneous, continuous behav
30、ior; and application of this practice may not be appropriate. Values expressed in this Handbook are in accordance with the International System of Units (SI) and American Society for Testing and Materials (ASTM) SI10, American National Standard for Use of the International System of Units (SI): The
31、Modern Metric SystemRevision IEEE/ASTM SI10-1997. 2. APPLICABLE DOCUMENTS 2.1 General The documents listed in this section are applicable to the guidance in this Handbook. 2.1.1 The latest issuances of cited documents shall apply unless specific versions are designated. 2.1.2 Non-use of specific ver
32、sions as designated shall be approved by the responsible Technical Authority. The applicable documents are accessible via the NASA Standards and Technical Assistance Resource Tool at https:/standards.nasa.gov/ or may be obtained directly from the Standards Developing Organizations or other document
33、distributors. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NASA-HDBK-6007A APPROVED FOR PUBLIC RELEASEDISTRIBUTION IS UNLIMITED 8 of 22 2.2 Government Documents None. 2.3 Non-Government Documents Harris, D. C. (1999). Materials for Infrared Window
34、s and Domes. Bellingham, WA: SPIE Optical Engineering Press ASTM International ASTM C1145 Standard Terminology of Advanced Ceramics ASTM C1161 Standard Test Method for Flexural Strength of Advanced Ceramics at Ambient Temperature ASTM C1273 Standard Test Method for Tensile Strength of Monolithic Adv
35、anced Ceramics at Ambient Temperatures ASTM C1424 Standard Test Method for Monotonic Compressive Strength of Advanced Ceramics at Ambient Temperature ASTM C1495 Standard Test Method for Effect of Surface Grinding on Flexure Strength of Advanced Ceramics ASTM C1499 Standard Test Method for Monotonic
36、Equibiaxial Flexural Strength of Advanced Ceramics at Ambient Temperature ASTM SI10 American National Standard for Use of the International System of Units (SI): The Modern Metric SystemRevision IEEE/ASTM SI10-1997 Institute of Electrical and Electronics Engineers (IEEE) IEEE SI10 American National
37、Standard for Metric Practice 2.4 Order of Precedence This Handbook provides guidance for material removal processes (i.e., machining or grinding) for advanced ceramics but does not supersede nor waive established Agency requirements/guidance found in other documentation. Provided by IHSNot for Resal
38、eNo reproduction or networking permitted without license from IHS-,-,-NASA-HDBK-6007A APPROVED FOR PUBLIC RELEASEDISTRIBUTION IS UNLIMITED 9 of 22 3. ACRONYMS AND DEFINITIONS 3.1 Acronyms C degrees Celsius m micron ASTM American Society for Testing and Materials CFCCs continuous fiber ceramic compos
39、ites IEEE Institute of Electrical and Electronics Engineers kPa kilopascal m meter MIL military min minute mm millimeter NASA National Aeronautics and Space Administration OD outer diameter sec second SI International System of Units 3.2 Definitions The following definitions of applicable terms are
40、taken from ASTM C1145, Standard Terminology of Advanced Ceramics, or are specific to this Handbook: Advanced Ceramic: A highly engineered, high-performance, predominately non- metallic, inorganic, ceramic material having specific functional attributes. Extraneous Flaws: Strength-limiting flaws intro
41、duced on the surface of test specimens or the component being designed. Note: An example is machining flaws in ground bend specimens that will not be present in as-sintered components of the same material. Fractography: The analysis and characterization of patterns generated on the fracture surface
42、of a test specimen. Note: Fractography can be used to determine the nature and location of the critical fracture origin. Intrinsic Flaws: Strength-limiting flaws that exist throughout the volume of a test specimen or component. Note: Examples are pores and agglomerations that are formed during proce
43、ssing and consolidation of the advanced ceramic. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NASA-HDBK-6007A APPROVED FOR PUBLIC RELEASEDISTRIBUTION IS UNLIMITED 10 of 22 Machining Damage: As used in fractography, chips and surface or subsurface
44、microcracks, striations, and scratches created during the machining process. Slow Crack Growth: Sub-critical crack growth (extension) that may result from, but is not restricted to, such mechanisms as environmentally assisted stress corrosion or diffusive crack growth. Note: In ceramics literature,
45、“slow crack growth curve” is often called a “static fatigue” curve. 4. GUIDANCE 4.1 Significance and Use 4.1.1 Scope This Handbook may be used for material development, material comparison, quality assurance, characterization, and design data generation. 4.1.2 Extraneous Flaws Generally, strength di
46、stributions of ceramics are probabilistic and can be described by a weakest link failure theory (Harris, 1999). These strength distributions can be related to distributions of both extraneous and intrinsic flaw distributions. In determining the intrinsic strength distribution of an advanced ceramic,
47、 it is important to limit the effect of extraneous flaws, particularly those introduced by machining, grinding, lapping, and polishing the test specimens. 4.1.3 Application-Matched Machining In cases where customary or application-matched machining or grinding procedures have not been developed, a c
48、onsistent, recommended machining or grinding practice can be useful as a starting point for developing such procedures. 4.2 Interferences 4.2.1 Fabrication Effects Fabrication of specimens can introduce dimensional variations and/or damage that may have pronounced effects on measured mechanical properties and behavior. Machining effects introduced during test specimen preparation can interfere in determining the ultimate strength of pristine materials. Surface preparation can also lead to the introduction of residual stres
