Envalior has developed Xytron M5080ET, a polyphenylene sulfide (PPS) compound for overmolding electric vehicle (EV) busbars exposed to high temperatures and repeated thermal cycling.
The impact-modified material is intended for busbars operating above 150° C, including those used in power control units and electric drive axles. Envalior says the material was developed in response to higher electrical loads and increasingly compact EV powertrain designs.
Xytron M5080ET is primarily designed for busbars that must withstand temperatures above 150° C. The material exhibits over 70% higher stress crack resistance in thermal shock tests at temperatures between -50° and 180° C compared to similar PPS compounds. (Image: Envalior)
EV busbars typically use copper conductors overmolded with plastic for electrical insulation. Because copper and plastic expand at different rates, repeated temperature changes can create stress within the overmolded material and contribute to cracking.
Xytron M5080ET is designed with a coefficient of thermal expansion closer to that of copper. According to Envalior, this helps reduce stress during abrupt temperature changes and improves resistance to cracking.
In thermal shock testing from -50° to 180° C, the compound demonstrated more than 70% higher stress-crack resistance than comparable PPS materials. Envalior also reports that weld lines formed where melt fronts meet were approximately 17% stronger.
The compound contains 50% glass fiber and mineral reinforcement by weight. It is designed to maintain dimensional stability while providing the mechanical and electrical properties required for busbar overmolding.
Xytron M5080ET achieves a UL 94 V-0 flame rating at a 2-mm specimen thickness. Envalior also reports that the material maintains high volume resistivity and dielectric strength before and after aging at elevated temperatures.
Low water absorption and high creep resistance are intended to help maintain dimensional stability over the service life of the component.
The material is intended for EV busbars that connect high-voltage battery, drive, control, and charging systems. Envalior says several customer development programs have already been completed for potential series-production applications.
Filed Under: Power Electronics, Technology News