Magnetic chains up to 10 μm in length formed of hollow cobalt mesospheres (480–850 nm) with a 60 nm thick shell are synthesized by a new soft‐assembly protocol. The obtained chains show a saturation magnetization of 37.5 emu g–1, a remnant magnetization of 1.55 emu g–1, and a coercivity of ca. 66 Oe at 300 K. A possible mechanism for the formation of the chainlike hollow structures is proposed.

It is well known that the no-chip machining process, burnishing, can easily improve surface roughness, waviness and hardness. To get the practical useful parameters, the effects of various burnishing parameters (spindle speed, depth, feed, burnishing radius and lathe) on surface roughness and waviness of the non-ferrous components were studied experimentally with a theoretical analysis. The experiments were conducted with a simply designed cylindrical surfaced polycrystalline diamond tool developed by us. It was found that smaller parameters do not mean lower surface roughness or waviness and different optimum burnishing parameters can be got under different burnishing conditions.

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According to the results obtained from the boundary condition study of the burnishing process, cylindrical polycrystalline diamond (PCD) tools have been designed and fabricated. We probe deeper in the burnishing process by comparing the mechanics of using cylindrical PCD tools to work on aluminium alloy and brass compared to turning. The empirical equations of three components of the burnishing force were established with the aid of a quartz force measuring system and statistical methods. The results obtained show that the distributions of force are different between burnishing and turning. Furthermore, the effect of the burnishing parameters on the burnishing force and the surface microhardness of the workpiece were examined with theoretical analysis. Here, it was concluded that the burnishing feed and depth are the most significant factors affecting the burnishing force and surface microhardness.

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