Abstract: A forming method wherein a billet (31, 66, 77, 87, 107, 128, 136, 144, 153, 77B, 77C) comprising a metal-based composite material (27) prepared by mixing an aluminum alloy (22) and a ceramic (15) is subjected to pressure forming to manufacture a formed article, which comprises carrying out the pressure forming by the use of different compression ratios for different portions of the formed article, wherein a compression ratio means the ratio of the height of a billet before the pressure forming to height of the billet after the pressure forming. The above forming method allows the manufacture of a formed article having different volume contents 8 Vf) of the ceramic for different portions thereof.

Abstract: A brake drum has its strength elevated in its disk portion. The brake drum is formed from a composition having ceramics dispersed in a matrix. The disk portion has a high ceramic content and thereby a high strength. Its cylindrical portion has a ceramic content decreasing gradually from the outer edge of the disk portion.

Abstract: A double coated pressure sensitive adhesive sheet used for fixing a part of an electronic device including an adhesive layer. At least one of the adhesive layers of the double coated pressure sensitive adhesive sheet has a maximum of loss tangent in a frequency region equal to or larger than a maximum characteristic frequency generated by a shock when the electronic device falls. The maximum of the loss tangent is equal to or greater than 1.

Abstract: On the surface of a developing roller disposed closely to a photosensitive drum, a toner supplied from a toner container to the surface is spread into a thin layer by a toner distribution and charging blade. The triboelectric charge, q.sub.1, of the toner and the triboelectric charge, q.sub.2, of the surface of the toner distribution and charging blade are equalized in polarity and made to satisfy a relation, .vertline.q.sub.2 .vertline.<.vertline.q.sub.1 .vertline.. The triboelectric charge, q.sub.3, of the surface of the developing roller is made to satisfy a relation, -4.0.ltoreq.q.sub.1 /q.sub.3 .ltoreq.-1.2. The triboelectric charge of the toner, q.sub.1, and the triboelectric charge, q.sub.4, of the surface of a recovery blade for recovering the residue of toner adhering to the developing roller are equalized in polarity and, at the same time, made to satisfy a relation, .vertline.q.sub.4 .vertline.<.vertline.q.sub.1 .vertline..