CERAMIC ENVELOPE DEVICE, LAMP WITH SUCH A DEVICE, AND METHOD OF MANUFACTURE OF SUCH DEVICES

摘要

This invention involves a new type of feedthrough-plug member for metal halide H ID lamp using PCA envelopes. The construction of the lamp housing consists of a PCA envelope and specially designed axially graded alumina-metal cermet multi-layers to eliminate cracking in cermet or PCA due to thermal stresses arising from thermal expansion mismatch. The fills are metal halides such as Na-Sc-I, rare earth halides, Hg, S n, and inert gases. The PCA vessel and directly sealed cermet-feedthrough assemblies al low the metal halide lamps to operate at high wall temperatures with better lumen output , color temperature, and CRI.