The potential for copper/brass looks good for model year 2000 diesel-powered vehicles, according to the people at the International Copper Association (ICA; New York City).
It’s like this: Emissions regulations in the U.S. are going to become much more stringent. The diesels will require better volumetric efficiency in order to achieve more complete combustion, thereby reducing emissions. Typically, diesels employ turbochargers and charge air coolers (CACs) to increase engine power and fuel economy. According to the ICA, a means by which the new emissions standards will be met is through an increase in the inlet pressure to the engine. And greater pressure leads to more heat. Which is where the copper/brass shines.
|Copper/brass can take the heat in diesel engines.|
Apparently, the average inlet temperature in today’s CACs is 190°C. And the estimate is that the average temperature will have to go to 246ºC. Which is something that copper/brass can handle. According to the ICA, the Cuprobraze manufacturing process can produce CACs that can perform at 290ºC with no metal fatigue—something that the association claims aluminum is incapable of because of a decline in aluminum’s tensile strength starting at 150ºC.
The colored squares in the image on the following page are actually two 3 x 3 x 1/8-in. pieces of plastics. Infrared photography is the cause of the colors, with the following relationships: white, 47º°C; red, 40°C; yellow, 35°C; green, 31°C; aqua, 26°C; blue, 23°C. The heat is a result of applying a 5-watt heat source to the center of the two coupons.
The bulls-eye adorned plastic is, in the parlance of the people from Cool Polymers (Warwick, RI) a “standard plastic,” a polypropylene. The field of green is their thermally conductive polymer, CoolPoly, a material that has found applications in products like personal computers, and which is said to have applicability in a variety of automotive applications (e.g., fluid/air or fluid/fluid heat exchangers; passenger interface components; electronic enclosures; electric motor encapsulation; sensors).
One of the main points of difference between the two materials at test here is that from the center to the edge the temperature variation across the conductive material is 4°C; it is 24°C across the polypropylene. Because the former is a conductor (and the latter an insulator), the dissipation of heat is better, which gives rise to the material’s moniker.
Auto glass is getting more robust all the time. Solutia Inc. (St. Louis) offers a line of what’s known as “Enhanced Protective Glass” (EPG), which can be used for side window and backlight installations, and which is used in vehicles including the Volvo S80, Audi A8, and Mercedes S-Class.
|While many plastic materials are insulators (such as the colorful one in this image), CoolPoly conducts heat, thereby offering a number of inherent advantages for heat-related applications.|
In a controlled demonstration, it required 20 seconds to break through standard EPG. By way of contrast, standard tempered glass withstood just two seconds of engineered pounding.
The EPG has a sandwich construction: Two pieces of heat-strengthened float glass (each about 2.1-mm thick) with a ~0.76-mm layer of polyvinyl butyral (PVB) in between.
Looking for a way to increase the performance of the EPG, it was initially thought that increasing the thickness of the PVB would be the answer . . . but it was determined that while the resistance to penetration was improved but the material essentially exhibited a folding such that a brigand could simply pull the impacted glass out of the window frame. So the Solutia engineers came up with a new solution called the “High Security Interlayer.” This is a more-complex sandwich: glass/PVB/polyethylene terephthalate (PET)/PVB/glass.
This withstood breakthrough for more than two minutes. And what’s more, it helps reduce road noise, too.