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Induction cladding TiB/Ti composite coating was in-situ synthesized by induction heating the preplaced powder mixture of 90% Ti (atom fraction, the same below) and 10% boron on a Ti6Al4V substrate. The microstructure, phase composition and micro/nano mechanical properties of the coating were studied by scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), X-ray diffraction (XRD), microhardness tester and nanoindentation tester. The results indicate that the composite coating has a smooth surface and a dense microstructure without cracks and pores. A strong metallurgical adherence is formed between the coating and the substrate. During induction cladding process, B and Ti are fully reacted to in-situ form TiB reinforcements. The matrix of the coating consists of α-Ti phase and a few β-Ti phases. The reinforcements of in-situ synthesized TiB are uniformly distributed in the coating with a volume fraction about of 9.4%. Indentation hardness and modulus of the in-situ TiB particles are about 35 GPa and 545 GPa, respectively, which cause the increase of the microhardness of the composite coating to about 525HV0.2. It is increased by 67% as against the Ti6Al4V substrate.

Tribological properties of oleic acid modified natural serpentine ultrafine mineral powders as lubricating oil additive were investigated by a reciprocating sliding wear tester. The effects of the four factors including load, reciprocating frequency, sliding time and concentration of serpentine on the properties of serpentine additive were analyzed. Results indicate that the anti-wear and friction-reducing properties of the base oil are significantly improved by the addition of the modified serpentine powders. The order that affects the friction-reducing performance of the serpentine additive is:concentration, reciprocating frequency, load, sliding time, and the optimal tribological conditions are 100 N, 5 Hz, 180 min, 0.5%(mass fraction). While that affects the anti-wear property is:load, concentration, reciprocating frequency, sliding time, and the optimal conditions are 100 N, 50 Hz, 180 min, 0.3%. Serpentine minerals forms a tribofilm consisting of various oxides, graphite and organic compounds on the friction surface, which is the key to improving anti-wear and friction-reducing properties.

To reveal the mechanical properties of thermal spray coating on different scales,flame spray NiCrBSi coating with average thickness 750μm was prepared on 45 carbon steel substrate, the mechanical properties, elastic-plasticity and indentation deformation of coating surface and cross-section were studied by nanoindentation. Results indicate that scale-dependent behaviors of coating mechanical properties were observed as a function of indentation depth for either the coating surface or the cross-section. The nano hardness, modulus and elastic-plasticity of coating decrease with the increasing indentation depth. The coating surface exhibits higher elasticity than the coating cross-section, the ratio of elastic work to the total indentation work, ηIT, of coating surface is 52% at the depth of 500nm, while that of coating cross-section is 40%; moreover, the coating cross-section possesses higher hardness and modulus than the coating surface; the corresponding values of the coating crosssection are 28% and 33% at the depth of 2000nm, higher than those of the coating surface, respectively. The indentation marks show ideal plastic deformation, pile-up and sink-in, and cracks. The difference of ηIT values between coating surface and cross-section decreases with the increasing indentation depth. It reaches about 35% at the depth of 2500nm from the both coating directions. For the coating splat structure,hardness and elastic modulus are the same in different directions,besides, with the increasing indentation depth, larger volume is involved in the indentation. The influence of the surrounding splats (especially the pores, cracks or grain/splat boundaries) on the measured coating properties is enhanced gradually,leading to differences in the appearance between different coating directions, as well as the decrease of coating hardness, elastic modulus.

Biological researches have attracted wide attentions in recent years, mimicking the morphology of creatures, learning the function of morphology and applying it to the engineering area have become the research focus. Investigating the special function of bionic surface texturing based on geometric morphology can provide us ideas to optimize surface properties of materials,extend the materials service life, widen the scope of application of materials, and improve the application values of materials. Through studying on the principle and application of hydrophobicity, bionic drag reduction, antifriction and wear-resistant due to the geometric morphology, the different functions of bionic texturing were explored, the future development directions of focusing on bionic patterns preparation and mechanism exploration were clarified, and further the surface treatment on materials was carried out to prepare the materials with more superior properties.

The latest research progresses on Fe-based amorphous coatings were reviewed. The typical alloy system and the classification of Fe-based amorphous coatings were clarified. The status, progress and development of the Fe-based amorphous coatings prepared by thermal spray processing and laser cladding process were discussed. The main mechanical properties and potential applications of the Fe-based amorphous coatings were also described. Furthermore, based on the main problems mentioned above, the future development of the Fe-based amorphous coatings was discussed, including the exploitation preparation technologies of high amorphous content of the Fe-based coatings, the development of the low cost and high performance Fe-based coating alloys system, the broadening application of Fe-based amorphous coatings, and so on.

The temperature field of FeCrNiCu alloy forming layers of continuous wave(CW) and pulsed laser remanufacture was analyzed using the non-contact infrared thermometer.The general rule of temperature field distribution of molten pool and heat-affected zone of the two modes was obtained. The pulsed laser process superiority in heat input, forming deformation control and reducing the temperature in molten pool and heat-affected zone was vilidated. The results show that during pulsed laser forming the peak temperature in the heat-affected zone is 730.4-810.5℃,the peak temperature in the molten pool is 998.7-1383.4℃,which are all obviously lower than the same process of the CW mode; the temperature-rise rate and cooling rate of pulsed laser are higher, which is helpful to the forming of fine grain structures and good mechanical performance; the forming experiment also further verifies more narrow heat-affected zone in pulsed laser process.

The tribological properties of attapulgite/oil-soluble nano-Cu composite lubricating additive were investigated by a SRV-Ⅳfriction wear tester. The worn surfaces were characterized by SEM and XPS. The results show that the two single additives can both improve the tribological properties of the base oil for a steel-steel friction pair,whereas the composite lubricating additive possesses more excellent friction-reduction and anti-wear properties than the single additives. The higher the load is, the better tribological properties the composite lubricating additive will show. In the effect of composite additive, a compact and smooth protective tribofilm composed by FeS2,Fe2O3,SiO2,Cu,FeOOH and organic compounds was formed on the worn surface.