Investigations on the Influence of Annealing on Microstructure and Mechanical Properties of Electrodeposited Ni-Mo and Ni-Mo-W Alloy Coatings

Ni-Mo and Ni-Mo-W coatings were electrodeposited on a stainless steel sheet, and then were annealed at 200, 400, and 600 °C. The effect of annealing heat treatment on the microstructure of Ni-Mo and Ni-Mo-W electrodepositions, their nano-hardness, and tribological properties were investigated. It was revealed that the average crystalline are refined and phase separation are promoted with formation of Mo-W related intermetallic precipitates at temperature exceed 400 °C on account of the co-existence of Mo-W elements within Ni-Mo-W coatings. Annealing heat treatment leads to hardening, and the hardness and elastic module increase significantly. The grain boundary (GB) relaxation and hard precipitated intermetallic particles are responsible for the annealing-induced hardening for ≤400 °C annealed and 600 °C annealed Ni-Mo-W coatings, respectively. In addition, both adhesive wear and abrasive wear are observed for coatings, and abrasive wear becomes predominant when annealing temperature up to 600 °C. The wear resistance of coatings is improved eventually by formation of a mixture of lubricated oxides upon annealing at 600 °C and the enhancement of H/E ratio for ≤400 °C annealed Ni-Mo-W coatings.

The effect of die radius on thickness distribution of SS304 stainless steel sheet in deep drawing of cylindrical cup

Thickness distribution of deep drawing products has been studied in recent decades since it has a significant influence on the product quality. In this paper a numerical simulation with experimental verification was conducted to examine the influence of die radius on the thickness distribution of cilindrical cup in deep drawing for SS304 stainless steel. Thickness distribution of the cup was analyzed through the stress-strain state during deep drawing by Deform 3D software. The obtained results allow choosing a reasonable die radius to achieve more uniform wall thickness of the cup, that optimizes tool design and reduces manufacturing costs.

A continuous high voltage electrostatic field system for thawing food materials

A laboratory continuous HVEF thawing system was designed and constructed in accordance with standards for food machinery. Corona discharge in wire-plate electrodes was considered for the system and a stainless-steel sheet was utilized as the conveyor belt. Corona flow was created by applying high voltages of 15, 20, and 25 kV and electrode gaps of 6, 8, and 10 cm. To evaluate the system, frozen tylose MH4000 gel with a moisture content of 77% w.b. as a meat analog was thawed from −10 to 0°C. The thawing duration which was mostly devoted to increase the temperature of control sample (no electrostatic field), considerably decreased when thawing the gel in the presence of the high voltage. High voltage and EG indicated significant effect on both thawing duration and specific energy consumption (p˂0.0001). The thawing duration decreased significantly by decreasing the electrode gap and increasing the applied voltage. In terms of energy consumption, the best condition (minimum specific energy consumption of 10.33 kJ kg-1) was obtained for the voltage of 15 kV, and the electrode gap of 10 cm.