Abstract: A thermally insulating piston for internal combustion engines is provided on the piston crown or in its dished combustion space portion with a thermally insulating liner which on the side thereof facing the combustion space consists entirely of a ceramic material, and which on the side thereof facing the piston crown or its dished combustion space portion has a metallic or metal-ceramic material fused with the piston metal.

Abstract: A selectively absorbent layer for solar collectors, comprising a mixture of chromium oxides resulting from thermal decomposition of chromium hexacarbonyl or substituted chromium carbonyl. The absorbent layer is deposited from a process gas containing the carbonyl gaseous phase, oxygen, and inert carrier gas. An intermediate reflective layer is provided between the absorbent layer and the substrate.

Abstract: A method for the production of homogeneous coatings of a substance comprising at least two metals and/or metal compounds on a substrate, which method comprises depositing the substance from a gas or liquid phase from dinuclear or polynuclear mixed metal compounds via a four step process comprising heating the substance to 85-90% of a final temperature over a period of 5 to 20 minutes, reducing the temperature to a second temperature which is 2/3 of said final temperature, maintaining the second temperature for 11/2 to 21/2 hours, raising the second temperature over a period of 20 to 40 minutes, and maintaining the final temperature for 1 to 2 hours. The coated materials are, for example, useful for coating solar collectors with an .alpha. of at least 0.70 and an .epsilon. no greater than 0.30.

Abstract: Method for manufacturing solar absorption layers by electrodeposition of heavy metals, such as Ni and Co, from aqueous citrate solutions. The heavy metal citrates are produced by direct reaction of metal oxides or carbonates with citric acid. The electrolyte concentration is a maximum 5% and has a pH of between 8 and 11. The deposition process takes place at room temperature, bath voltages of 8 to 30 V, and current densities of 3 to 10 A/dm.sup.2. The layers produced by this method are well bonded black layers resistant to temperatures up to 700.degree. C.

Abstract: A method and apparatus for the nickel-plating of components, in which the finished component, which is to be nickel-plated, is heated to a temperature between 150.degree. and 200.degree. C. and is at the same time subjected to a continuously flowing gas stream containing nickeltetracarbonyl (Ni(CO).sub.4) and an entrainment gas. In this procedure nickel is constantly desposited from the gas phase on the heated surface from the gas stream which continuously flows around the finished component and consists of an entrainment gas and nickeltetracarbonyl. The nickel coating produced by this procedure adheres well, given normal pre-cleaning, and is practically seal-tight even in very thin coating thicknesses (0.1-1.mu.).