1、Automotive Carbon Fiber Composites From Evolution to Implementation Jackie D. Rehkopf SAE International technology profiles Automotive Carbon Fiber Composites T-124 Book.indb 1 11/22/11 9:06 AMOther SAE books of interest: Care and Repair of Advanced Composites By William Cole, Keith B. Armstrong, ph
2、one 877-606-7323 (U.S. and Canada only) or 724-776-4970 (outside U.S. and Canada); fax 724-776-0790; e-mail CustomerServicesae.org; website http:/books.sae.org. T-124 Book.indb 2 11/22/11 9:06 AMWarrendale, PA, USA Automotive Carbon Fiber Composites: From Evolution to Implementation By Jackie D. Reh
3、kopf T-124 Book.indb 3 11/22/11 9:06 AM Copyright 2012 SAE International. eISBN: 978-0-7680-7577-9400 Commonwealth Drive Warrendale, PA 15096-0001 USA E-mail: CustomerServicesae.org Phone: 877-606-7323 (inside USA and Canada)724-776-4970 (outside USA) Fax: 724-776-1615 Copyright 2012 SAE Internation
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6、 reliable. However, neither SAE International nor its authors guarantee the accuracy or completeness of any information published herein and neither SAE International nor its authors shall be responsible for any errors, omissions, or damages arising out of use of this information. This work is publi
7、shed with the understanding that SAE International and its authors are supplying information, but are not attempting to render engineering or other professional services. If such services are required, the assistance of an appropriate professional should be sought. To purchase bulk quantities, pleas
8、e contact: SAE Customer Service E-mail: CustomerServicesae.org Phone: 877-606-7323 (inside USA and Canada)724-776-4970 (outside USA) Fax: 724-776-1615 Visit the SAE Bookstore at http:/store.sae.org T-124 Book.indb 4 11/22/11 9:06 AM Automotive Carbon Fiber Composites | v Contents Executive Summary i
9、x Chapter 1 Introduction 1 1.1 A Brief History of Carbon Fiber Composites 2 1.2 Carbon Fiber Implementation Timeline . 2 1.3 Closing Thoughts .11 Chapter 2 Carbon Fiber Composite Constituents: Fiber and Resin Types for Automotive Applications .17 2.1 Carbon Fiber Primer 18 2.1.1 Carbon Fiber History
10、 .20 2.1.2 Carbon Fiber Developments .22 2.1.3 Developments in Conversion Processes and Post-Treatments .28 2.1.4 Future Developments Around the Carbon Fiber 29 2.2 Resins for the Automotive Industry 29 2.2.1 Characteristics of Different Resins Used in CFCs 30 2.2.2 Resin Developments .31 2.2.3 Resi
11、ns with Reduced Cure Time 31 2.2.4 Resins with Targeted Performance 32 2.2.5 Resins for Targeted Processing Methods .33 2.3 Closing Thoughts .34 Chapter 3 Carbon Fiber Composite Construction .39 3.1 The Splendid Variety of CFCs for Automotive Applications 40 3.2 Fiber Reinforcement Forms .42 3.2.1 B
12、onded .42 3.2.2 Unidirectional Tapes .42 3.2.3 Stitched 42 3.2.4 Knits 43 3.2.5 Wovens .43 3.2.6 Braids .45 T-124 Book.indb 5 11/22/11 9:06 AMvi | Automotive Carbon Fiber Composites 3.3 Constructions .46 3.3.1 Laminates 46 3.3.2 Filament Winding 47 3.3.3 Stitching Preforms .48 3.3.4 Three-Dimensiona
13、l Braids .48 3.3.5 Nanostitching and Fuzzy Fibers .49 3.4 Closing Thoughts .50 Chapter 4 Manufacturing Processes for Carbon Fiber Composites.53 4.1 Introduction 54 4.2 Injection Molding 55 4.3 Compression Molding 56 4.4 Thermoforming56 4. 5 Sheet and Strand Molding Compound 57 4.6 Spray Forming 57 4
14、.7 Pultrusion 57 4.8 Filament Winding 58 4.9 Resin Infusion Processes 59 4.10 Out-of-Autoclave Processing of Structural Components .60 4.11 Quickstep Process 62 4.12 Preforming Processes .62 4.13 Other Processes .63 4.14 Tooling .63 4.15 Closing Thoughts .65 Chapter 5 Machining and Joining .69 5.1 M
15、achining .70 5.1.1 Tool Drilling .70 5.1.2 Tool Wear Compensation .73 5.1.3 Tool Cutting/Trimming .74 5.1.4 Abrasive Waterjet Cutting 74 5.1.5 Laser Cutting .76 5.2 Joining .76 5.2.1 Bonding .76 5.2.2 Mechanical Fasteners .79 5.3 Closing Thoughts .82 T-124 Book.indb 6 11/22/11 9:06 AM Automotive Car
16、bon Fiber Composites | vii Chapter 6 Reclaiming/Recycling Carbon Fiber Composites .85 6.1 Introduction 86 6.2 Reclaiming and Recycling CFCs88 6.3 Implementation of Recycled CFCs .90 6.4 Closing Thoughts .92 Chapter 7 Implementation and Longevity .95 7.1 Design and Modeling .96 7.1.1 Fiber Orientatio
17、n and Composite Construction .96 7.1.2 Computer Aided Engineering .97 7.1.3 Mechanical Behavior of CFCs 97 7.2 Physical Testing 99 7.3 Quality Control .100 7.4 Non-Destructive Evaluation 101 7.5 Repair .104 7.6 Closing Thoughts .105 Chapter 8 Concluding Thoughts .107 8.1 Manufacturing and Assembly i
18、n Legacy Plants .108 8.2 Advancing with the Advancements of Other Materials .109 8.3 Industry and Public Acceptance.113 8.4 Closing Thoughts .115 About the Author .117 T-124 Book.indb 7 11/22/11 9:06 AMT-124 Book.indb 8 11/22/11 9:06 AM Automotive Carbon Fiber Composites | ix Executive Summary The a
19、dvantages of carbon fiber composites (CFCs) in automotive design are high stiff- ness, high specific strength (strength-to-weight ratio), excellent fatigue endurance, cor- rosion resistance, generally good impact resistance, and flexibility in design that permits them to be tailored to design requir
20、ements. Composites also facilitate a lower parts count by reducing the number of subassemblies and fasteners. Replacing metal with CFCs can provide significant weight reduction, which has become particularly important in our current society that is facing high fuel prices and much more stringent emi
21、ssions standards. Aside from passenger vehicles, heavy-duty on-highway trucks and military vehicles are also exploring the use of CFC components to enable better fuel economy and/or increase payload. Unfortunately, CFCs also have notable disadvantages, including relatively high material and fabricat
22、ion costs, poor compressive and shear properties, and the necessity for non-destructive inspection techniques to detect flaws or damage. The main factors in the automotive industry driving fiber development and resin de- velopment center around cost, performance, cure time, and processing method. Th
23、e years 2010 and 2011 have seen an incredible amount of cooperation and partnerships between companies operating at different points in the value stream to bring new ma- terials and processing technologies to market quicker. Carbon fibers and matrix res- ins, and their developments, are not independ
24、ent of the other aspects of manufactur- ing a carbon fiber composite component, nor are they necessarily independent of each other. Different resins process differently with regard to the time, temperature, and pressure required for fiber wet-out and consolidation. Additionally, different fiber-res-
25、 in constructions require different processing methods. Selecting the right fiber, resin, and construction for a particular application requires knowledge of not only the fiber and resin material properties, but also of the method of manufacturing. The method of manufacturing influences the composit
26、e construction and end properties, while the surface quality of the finished part (Class A or non-Class A) and the production vol- umes to be made in turn dictate what manufacturing methods are technically and eco- nomically viable. One must also factor in the commercial competitiveness with other m
27、aterials with regard to vehicle installation, maintenance, and lifecycle issues. There is usually more than one way to make a carbon fiber composite automotive part, and all factors should be considered to make the best decision. Both the aerospace and automotive industries are driving changes in ca
28、rbon fiber composite technology to produce components that have lower material cost and tar- geted performance. Those developments will in turn lead to some developments in the manufacturing processes. For example, changes in processing temperatures can result in changes in tooling materials and hea
29、t sources, and changes in composite construc- tion can lead to changes in material handling during component manufacture. Such future advancements driven by raw material and construction improvements will be additive to the advancements driven directly by the manufacturing process to improve areas s
30、uch as part-to-part cycle time and energy efficiency.x | Automotive Carbon Fiber Composites One of the most challenging aspects of implementing CFC components in vehicle de- sign is attaching them to the rest of the vehicle. This usually requires machining and joining, which must be done in a manner
31、 that retains the mechanical properties of the CFC component as well as possible, provides a strong and durable joint, is cost-effec- tive, and fits with the OEM assembly process and vehicle production rate. Worldwide, automotive companies are facing some challenging energy and environ- mental issue
32、s. In the U.S., the 2010 Corporate Average Fuel Economy (CAFE) regula- tion that increased fuel economy from 27 to 35 miles per gallon by 2016 has already re- sulted in concerted efforts to implement more lightweighting materials, including CFCs, in vehicle design. Means to recycle CFCs and other li
33、ghtweighting materials must be developed to just maintain the current level of recyclability of vehicles made predomi- nantly with steel. The CFC recycling industry is still in its infancy and the processes are expensive and complicated. The industry has formidable requirements, including consistent
34、 scrap availability, appropriate size reduction technologies, established process parameters, the infrastructure for material collection, and standardization of recyclate properties. The technical and economic issues with recycling/reusing CFCs are best developed during vehicle design to aid in both
35、 the recovery of the material as well as potential implementation of the recyclate back into a vehicle. Implementation and longevity of CFC components in mainstream vehicles hinge on a multitude of technical issues, covering raw materials, fabrication, assembly to other (CFC or non-CFC) components,
36、and in-vehicle performance. However, addressing all the tech- nical issues will not guarantee first-use or long lasting use of CFCs in mainstream vehi- cles. Acceptance of the material is also key the acceptance of CFCs by OEMs through the inclusion of CFCs in their portfolio of materials from which
37、 they can design main- stream vehicles, and acceptance by the consumers with regard to cost and performance throughout the vehicle life, which inevitably includes damage and repair. This is an exciting time for the carbon fiber composites and automotive industries. The current need to drastically li
38、ghtweight the U.S. vehicle fleet in the next few years pro- vides a great opportunity for CFCs to find prominence in mainstream vehicles. Their advantageous high specific modulus and strength can result in weight savings up to 60% compared to conventional steel designs. However, before CFCs find pro
39、minence, significant inroads in reducing the relatively high material and fabrication costs, long part-to-part cycle times, and slow assembly/attachment to other vehicle components will need to be made. Progress will also be needed in the areas of damage detection, repairability/replaceability, and
40、recycling. The combined chapters of this book highlight current activities surrounding automotive car - bon fiber composites and the anticipated direction of developments in the next 5-10 years. The objective is to provide a high-level view as opposed to technical treatises, preparing the reader for
41、 meaningful discussions with composites engineers and technicians, fiber suppli- ers, resin suppliers, tool and equipment manufacturers, as well as business development and lifecycle workers. The possibilities of carbon fiber composites in automotive applications are plentiful and more promising tha
42、n ever before in the history of the automobile. Automotive Carbon Fiber Composites | Chapter 1 | 1 Chapter One Introduction We must dare to think “unthinkable” thoughts. We must learn to explore all the options and possibilities that confront us in a complex and rapidly changing world. James W . Ful
43、bright T-124 Book.indb 1 11/22/11 9:06 AM2 | Automotive Carbon Fiber Composites | Chapter 1 1.1 A Brief History of Carbon Fiber Composites In the early 1940s, the defense industry spawned the industrialization of fiber rein- forced plastics (FRPs), particularly for use in aerospace and naval applica
44、tions. The U.S. Air Force and Navy capitalized on FRP composites high strength-to-weight and inherent resistance to weather and the corrosive effects of salt air and sea. The rapid development and use of composite materials beginning in the 1940s had three main driving forces: 1) Military vehicles,
45、such as airplanes, helicopters, and rockets, placed a premium on high-strength, lightweight materials; 2) The emergence of new, light- weight polymers offered solutions for a variety of uses, provided that something could be done to increase the mechanical properties of plastics; and 3) The extremel
46、y high theoretical strength of certain materials, such as glass fibers and carbon fibers, was be- ing discovered to solve the problems posed by the militarys demands. The 1950s brought new revolutionary applications for FRP composites. The same technology that produced the reinforced plastic for the
47、 Manhattan Project in World War II sparked the development of high-performance carbon fiber composite mate- rials for solid rocket motor cases and tanks. Carbon fibers have low heat expansion, high dimensional stability, high tensile modulus and strength, and they sustain these excellent mechanical
48、properties under high temperatures. The high potential strength of carbon fiber was realized in 1963 through a process de- veloped at the Royal Aircraft Establishment at Farnborough, Hampshire. The process was patented by the UK Ministry of Defence, then licensed by the National Research Development
49、 Corporation (NRDC) to three British companies: Rolls-Royce, which was already making carbon fiber, Morganite, and Courtaulds. They established indus- trial carbon fiber production facilities within a few years. Rolls-Royce took advantage of the carbon fiber composite properties to break into the American market with its RB-211 aero-engine using carbon fiber in the engines compressor blades. Unfortu- nately, during testing they proved vulnerable to damage from bird impact. In 1968 Rolls-Royces ambitious schedule for the RB-211 was endangered, and the problems b
