SAE AMS 6891:2020 pdf download

SAE AMS 6891:2020 pdf download Carbon Fiber and Fiberglass Epoxy Prepreg Products with 350 °F (177 °C) Cure for Aerospace Applications
1. SCOPE The intent of this specification is for the procurement of carbon fiber and fiberglass epoxy prepreg products with 350 °F (177 °C) cure for aerospace applications; therefore, no qualification or equivalency threshold values are provided. Users that intend to conduct a new material qualification or equivalency program must refer to the production quality assurance section (4.3) of this base specification, AMS6891.
1.1 Form This specification and its associated detail specifications establish the requirements for a 350 °F (177 °C) autoclave cure, continuous fiber (“unidirectional tape and fabric prepreg”) impregnated with a modified B-staged epoxy resin.
1.1.1 Detail Specification This base specification contains basic fiber reinforced epoxy prepreg material requirements that apply to every product. The detail specifications contain additional or superseding properties and requirements that apply to a specific product.
1.2 Purpose
a. The purpose of this specification is to allow procurement of a defined material corresponding to the statistically derived material properties published in CMH-17 (formerly MIL-HDBK-17).
b. The materials qualified to this specification are designed specifically for vacuum-bag autoclave cure (see 4.4.9).
c. This specification is developed based on the material properties that are available publicly. The user may specify additional requirements beyond those defined in this specification, especially when the user has generated additional material properties beyond those available publicly or when the application has other requirements. The additional requirements are subject to supplier review and approval.
d. The use of this specification does not guarantee material or structural performance. Users should be actively involved in evaluating material performance and quality including, but not limited to, performing regular user quality control tests, performing periodic equivalency/additional testing, participating in material change management activities, conducting statistical process control, and conducting regular supplier audits.
e. This material is intended for use in laminate applications with a service temperature up to 250 °F (121 °C).
1.3 Classification
1.3.1 Form
Form specifies the basic material form. For example:
Form 1: Unidirectional prepreg for hand layup applications
Form 2: Unidirectional prepreg tape for automated tape laying equipment
Form 3: Unidirectional prepreg tape for automated fiber placement
Form 4: Woven fabric prepreg for hand layup applications
Form 5: Woven fabric for automated tape laying equipment
1.3.2 Type
Type specifies the nominal prepreg resin content. For example:
Type 35: Nominal resin content 35% by weight
1.3.3 Class
Class specifies the basic fiber type used in the prepreg. For example:
Class 1: Intermediate modulus carbon fiber
Class 2: Standard modulus carbon fiber
Class 3: S-glass fiber
Class 4: E-glass fiber
Class 5: High modulus carbon fiber
1.3.4 Grade
Grade specifies nominal fiber areal weight in grams per square meter (gsm). For example:
Grade 190: 190 gsm nominal fiber areal weight
1.3.5 Style
Style defines the fiber filaments and construction of the fabric prepreg or list the appropriate industry standard style (not applicable to non-fabric products). For example: