Corning Smartphone Glass Shaves Weight From 2017 Ford GT

Given the numerous challenges faced by the auto industry today as it tries to meet future fuel economy and CO2 emissions standards, one might wonder why Ford is expending resources on a low volume supercar like the GT.  From the perspective of Ford, the Le Mans-bound GT is both a marketing brand builder and more importantly a real-world testbed for the technologies and features that will help mainstream models like the Focus and Fusion meet those daunting challenges. Hau Thai-Tang, Ford group vice-president for global purchasing identified powertrain, aerodynamics and mass reduction as the three critical areas in developing the GT with glass-maker Corning making an important contribution to the latter.

When the topic of discussion turns to advanced automotive technology, glass isn't typically high on the agenda. However, glass is a big contributor to vehicle mass. Even on a small car like the Focus, the 50 square feet of glass weighs about 80 pounds, a figure that jumps to over 100 pounds on larger vehicles like the Explorer. Adding one of those increasingly popular panoramic moonroofs can double the glass weight in a car.

With mass being the enemy of both performance and efficiency, Ford turned to long-time supplier Corning more than two years ago while developing the multi-material lightweight vehicle (MMLV) concept. Based on the midsize Fusion sedan, Ford researchers used a variety of materials including magnesium, carbon fiber and lighter glass to cut the weight of the MMLV by 23 percent, bringing it in line with the much smaller Fiesta.

Corning stepped up with its well-known Gorilla Glass, a new glass formulation that saw its first broad commercial application in mid-2007 with the launch of the original Apple iPhone. When the iPhone was first announced in January 2007, it had a lightweight plastic screen. However, after several weeks of carrying a prototype in his pocket, the late Apple CEO Steve Jobs demanded that his engineering team find a solution that wouldn't be so susceptible to scratches. Since the launch of the iPhone, more than 4 billion Gorilla Glass equipped mobile devices have been shipped globally.

When the first GTs are delivered to customers in 2016, it will be the first production car equipped with a new hybrid Gorilla Glass windshield developed by Corning and Ford. Traditional windshield glass consists of two layers of soda lime glass sandwiching a central adhesive plastic central layer. The new system from Corning replaces the innermost layer with Gorilla Glass.

According to Corning, the new automotive grade Gorilla Glass is five times stronger per pound than standard glass. The extra strength enables the glass sandwich to be 30 percent lighter and 25 to 50 percent thinner depending on the application as well as more resistant to cracking from impacts. Conventional materials are typically 4 to 6 millimeters thick, while the hybrid laminate is just 3 to 4 millimeters.

In a demonstration at the Ford proving ground, a Corning engineer fired a 1.75-inch golf ball-sized chunk of ice simulating a hailstone at a sheet of conventional windshield glass at 55 mph, causing the inner layer of glass to shatter in a way that would have sent glass shrapnel into the cabin. When the same test was conducted with the new material, the Gorilla Glass remained intact.

Ford will use the hybrid glass sandwich for both the windshield and engine cover of the GT while a third sheet of pure Gorilla Glass will be used as a bulkhead window between the cabin and the engine compartment. Overall, the new glass has shaved 12 pounds from the GT helped lower the center of gravity by 3 millimeters.

In addition to the reduced weight, the Gorilla Glass has other advantages.

"Traditional glass is cut to shape using the long-standing score and break method," said Paul Linden, Ford body exteriors engineer. "A line representing the perimeter of the windshield is scored in the glass and the extra material if fractured off. This can lead to unevenness and stress points along the edge of the glass that make it more susceptible to cracking from a stone impact."

The new hybrid glass is laser cut, leaving a smoother edge that should contribute to making it more durable. Ford declined to discuss the cost of the new material, but did acknowledge that there should be only a minimal impact on service costs.  That should be welcome to owners of the first-generation Taurus in the late-1980s who got a sticker shock when replacing the heated windshield that debuted on that car.

In addition to weight savings, the Gorilla Glass windshield should enable other changes that contribute to enhanced fuel efficiency. Thai-Tang highlighted the advantages this new material should have projecting heads up displays. The reduced thickness and greater uniformity of the Corning glass reduces the optical distortion when looking through the glass at extreme angles. That will enable windshields to be tilted further back for a sleeker look and improved aerodynamics.

Over the past eight years, Corning's Gorilla Glass has helped to change the way we use mobile communication devices and it may now open up interesting new possibilities for automotive designer and engineers.