Nine-million-volt hunt for better fuel economy

When you think about having an X-ray taken, you may think about a broken bone or a trip to the dentist. Now a much more powerful X-ray machine is helping design automotive parts quicker and more efficiently at Ford.

While the technology is the same, a standard medical chest x-ray uses about 150 kilovolts – or 150,000 volts. That’s adequate for looking at bones and at steel up to about ¼-inch thick. The Ford X-ray uses nine megavolts – or nine million volts – and lets engineers analyze steel up to 20 inches thick.

In fact, Ford’s nine megavolt modern marvel is the largest privately owned, non-military X-ray in this part of the world and it lives in a building called the Non Destructive Testing Lab. While a medical radiologist uses a lead apron for protection, the Ford engineers seek shelter behind eight-foot walls made of solid, poured concrete.

What role does an X-ray serve in automotive engineering?

“We can examine the very molecular make-up of a car part, checking for cracks or other potential weaknesses,” said lab engineer David Gerke.

For example, Ford engineers used the lab to evaluate the parts of the new 3.5-liter V-6 engine. X-ray images helped engineers find unwanted soft spots in the aluminum engine block, created as molten metal cooled at an inconsistent rate. This information was used to alter the design, delivering the strongest, most reliable engine block possible. In addition, areas of unneeded strength were refined to save weight – improving fuel economy.

“We also can reverse engineer parts, which you can compare to a CAT scan,” Gerke explained.

“We layer x-ray images like slices of bologna to make a three-dimensional model. This model can be used in any number of computer-aided engineering tests such as durability, fluid flow, or noise, vibration and harshness tests. We do the same type of analysis that you would do on a computer-aided design (CAD) model, but we’re working with a real part.”

For example, Ford engineers used the lab to create three-dimensional models of several different intake manifolds for the 3.5-liter engine. Each design was then tested and benchmarked, measuring the amount of airflow per minute. Engineers then picked the manifold that provided the optimum amount of air to the engine, improving the engine’s performance feel and fuel economy.

The lab’s name comes from the old way of testing metal components. To determine metal thickness or porosity levels, engineers used to cut parts into small, manageable pieces to be viewed under a low-energy x-ray.

“At the end of that process,” said Gerke, “we handed over our results, and a box of scrap pieces. At the end of our new process, we return the whole part and say ‘it’s good, go make it.’”

Changing how the lab approached testing and analysis has delivered a more efficient way for Ford to make more reliable, lighter weight and more fuel-efficient automobiles.