Research On Material Selection And Friction And Wear Performance Of Key Friction Pair For Seawater Desalination Pump

Energy recovery is a key technology affecting energy consumption and cost performance of small and medium-sized seawater desalination plants,and seawater desalination pump is a major energy consumption equipment of energy recovery plants.Due to the special physical and chemical properties of seawater,friction pair materials of seawater desalination pump are faced with harsh working environment,and their key parts have short life and low working efficiency,so they need to be replaced frequently.Friction pair materials should not only choose low friction coefficient and wear rate,but also have excellent mechanical strength,wear resistance and corrosion resistance.According to the requirements of the subject,the key components of the seawater desalination pump with turbine,plunger and self-pressurizing allin-one machine are studied in this paper.The friction and wear test of TC4 titanium alloy with engineering plastics(PEEK,POM and its composites),alumina ceramic and metal alloy(TC4 titanium alloy,2205 duplex stainless steel and 316 stainless steel),and metal alloy and metal alloy were carried out in seawater environment.The main research work of this paper is as follows:(1)Firstly,the research status of friction pair materials in seawater environment at home and abroad is summarized,and the deficiencies of relevant materials in Marine environment are analyzed and summarized.Finally,the experimental research scheme of this paper is proposed.The stress of the key friction pair of the pump was analyzed,and according to the existing fixture and the contact form of the key friction pair of the testing machine,the pin-plate and thrust ring were determined to be used in the test.(2)The MM-W1 B vertical universal friction and wear testing machine was used to carry out the friction and wear test,and the wear amount of the sample before and after the test was measured with the help of a ten-thousandth balance.The influence law of external factors(load and speed)on frictional wear performance in seawater environment was investigated by using single variable test method,and compared with dry friction and pure water.The experimental results show that modified PEEK and TC4,2205 and alumina ceramics,TC4 and 2205 duplex stainless steel have better friction and wear performance in seawater and pure water environments.In dry friction environment,the friction and wear properties of POM-D and TC4 were better.(3)The primary and secondary effects of load,speed and environmental media on frictional wear performance were investigated by orthogonal test.The test results show that the environmental media is the main factor affecting the friction coefficient of 2205 and ceramic mating pairs,and the load is the main factor affecting the wear amount of 2205 and ceramic mating pairs.When TC4 is paired with alumina ceramics,the hardness of the ceramics is very high due to the small hardness of TC4,and the friction coefficient is smaller than the other two pairs,but the wear amount of TC4 is larger than 2205 and 316.(4)By means of microphase interface stereoscopic digital microscope and two-mode 3D surface profilometer,the surface morphology of the friction pair was observed and analyzed.The main wear forms of engineering plastics and TC4 are adhesive wear.The wear forms of metal and alumina are fatigue wear,abrasive wear and corrosion wear.The wear forms of metal and metal pair are mainly the interaction of fatigue wear,abrasive wear and corrosion wear.