Automotive Composites Require Specialized Quality Control and Inspection Standards (Part 1)

Posted on 3/29/2019 9:03:10 AM By ASC

Strong, lightweight composites combined with adhesives are among the ways auto manufacturers create safer, less polluting cars with an enhanced driving experience. But, strong as the combination can be, flaws can occur, making standardized testing and inspection vital to motoring safety.

Faults within Composites include:

  • Broken fibers
  • Delamination of layers
  • Debonding
  • Matrix cracks
  • Wrinkles, folds, or bunching
  • Resin-rich pockets
  • Foreign objects
  • Voids
  • Blisters
  • Porosity

Flaws in adhesive joints could be caused by:

  • Incorrect mixing of adhesive components
  • Incorrect placement of adhesive
  • Voids and inclusions
  • Inadequate surface preparation
  • Partial mold release removal
  • Incorrect amounts of adhesive applied
  • Incorrect curing

Until recently, contact between composites and metals and resulting galvanic corrosion has limited their combined use, but the new BMW i3 may be the shape of things to come. The passenger cell or “Life Module” is almost exclusively made from molded carbon fiber composite components bonded together with adhesives. The structure is fitted to an aluminum chassis using adhesives and mechanical fasteners.

Should this direction be the future of auto design, complications for quality control and testing will include the fact that composites can consist of several different types of layers.

The i3 already demonstrates this with a honeycomb structure to absorb impacts, braided carbon fiber, and a foam core. Soon, fiber-metal laminates like glass laminate aluminum reinforced epoxy or GLARE, already used in aerospace applications, are likely to be used in cars too, adding to the complexity of quality control and testing tasks.

Part 2 located HERE

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