A SiC nanoparticles reinforced ceramic composite coating (SiC_p/MAO) was successfully prepared on the YAl₂ particles reinforced Mg-Li based composite using micro-arc oxidation. The phase composition and morphology of coatings were characterized by XRD, EDS, SEM and 3D laser scanning microscope. The corrosion behavior of coatings in a 3.5 wt% NaCl solution was evaluated by immersion test, potentiodynamic polarization and electrochemical impedance spectroscopy. With the increasing of SiC nanoparticles amount, the surface morphology of the composite coating was more compact and uniform with the reduction of pore diameter and micro-cracks. Meanwhile, the thickness and surface roughness of the composite coating were decreased. Both immersion and electrochemical tests showed that the 2g/L SiC_p/MAO composite coating had the lowest corrosion rate, which proved that the addition of SiC nanoparticles improves the corrosion resistance of the composite coating.

The strength of Mg–Li alloy is greatly improved by the composite strengthening of intermetallic compound YAl₂ particles, but the low corrosion resistance of Mg–Li alloy is still the main factor that restricts the application of the alloy and its composites. In this paper, the effect of YAl₂ particles on the corrosion behavior of Mg–Li alloy was systematically investigated. The results showed that the corrosion resistance of YAl_2p/LA143 composite could be significantly improved, accounting for the formation of a transitional interface layer by adding YAl₂ particles. The diffusion of yttrium and aluminum atoms from YAl₂ particulates improved the stability of the surface film and enhanced the adhesion between the corrosion products and the substrate, which hindered further expansion of pitting.

In order to solve the problem of external corrosion of deep well casing in oil and gas fields, a new type of high-temperature-resistant zinc alloy sacrificial anode material was used. The temperature and corrosion resistance of the new anode material and TP140 casing were investigated by simulating the high-temperature working conditions of a deep well in an oil field using high-temperature and high-pressure corrosion tests and electrochemical tests. The results showed that at 100–120 °C, the corrosion rate of TP140 protected by a sacrificial anode was only one-tenth of that under unprotected conditions, and the minimum corrosion rate of TP140 protected by a sacrificial anode at 100 °C was 0.0089 mm/a. The results of the dynamic potential polarization curve showed that the corresponding corrosion current density of TP140 first increased and then decreased with the increase in temperature. The self-corrosion potential in sacrificial anode materials first increased and then decreased with the increase in temperature, and the potential difference with TP140 gradually decreased.

To explore a new method to improve the wear resistance of TiNi shape memory alloy (SMA), Ti-50.8Ni alloy was treated by the method of ultrasonic surface shot peening. The microstructure evolution, hardness, and tribological behaviors have been further investigated to evaluate the effect of ultrasonic surface shot peening (USSP). The surface microstructure can be refined to some extent while the basic phase composition has little change. USSP can facilitate the martensitic transformation in the surface layer, which benefits improving the surface hardness. Additionally, the hardness of Ti-50.8Ni alloy increases first and then decreases with the increase of applied load, but the USSP-treated alloy tends to be more sensitive to load. USSP treatment can improve the wear resistance and reduce the coefficient of friction (COF) in case of a low sliding wear speed of 5 mm/s. However, the tribological properties of USSP-treated alloy are reversely worse in the case of 10 mm/s. This is mainly attributed to the combined effect of stress-induced martensite transformation and degeneration resulting from the frictional heating during the dry sliding wear process.

Cooperatively controlled robots are used in many kinds of applications, including surgical robot applications where the surgeon can guide the robot end effector to a desired position. Often, a 6 degree-of-freedom (DOF) force/torque sensor is installed. However, in some cases, the sensor is only used to impose safety thresholds and to support the robot guidance task. In cases where high guidance accuracy is not required, it can be difficult to justify the added cost of a 6 DOF force sensor. One lower-cost solution is to incorporate a joystick or similar input device, but this requires additional hardware and removes the surgeon's hands from direct interaction with the robot end-effector. This paper presents a method for achieving cooperative force control without a force sensor. The method utilizes motor current feedback and uses a calibrated current value for force estimation. The novelty of this method is that it can be applied to non-backdrivable robots. It is implemented on a 2-DOF XY stage and experiments are conducted to demonstrate accuracy and performance on this non-backdrivable robot.