Heat Resistance of TiN Coated HSS Tools

The cutting friction, cutting deformation, producing heat, conducting heat, temperature field of TiN coated HSS tools in the cutting process are discussed profoundly. In order to make clear the heat property of TiN coated tools, from the micromechanism angle, the relationship of the heat property and the crystal structure of TiN compound is analyzed, and the regularity of TiN compound crystal structure changing with temperature rising is sought. The difference of the wear resistance and heat resistance of TiN coated tools deposited by c1 and c2 depositing techniques is proved by tests. The conclusions will offer the theoretical basis for correct design of geometrical parameters of TiN coated tools, rational selection of cutting regimes and optimization of the depositing technique.

Improvement of thickness uniformity and elements distribution homogeneity for multicomponent films prepared by coaxial scanning pulsed laser deposition technique

In conventional pulsed laser deposition （PLD） technique, plume deflection and composition distribution change with the laser incident direction and pulse energy, then causing uneven film thickness and composition distribution for a multicomponent film and eventually leading to low device quality and low rate of final products. We present a novel method based on PLD for depositing large CIGS films with uni- form thickness and stoichiometry. By oscillating a mirror placed coaxially with the incident laser beam, the laser＇s focus is scanned across the rotating target surface. This arrangement maintains a constant re- flectance and optical distance, ensuring that a consistent energy density is delivered to the target surface by each laser pulse. Scanning the laser spot across the target suppresses the formation of micro-columns, and thus the plume deflection effect that reduces film uniformity in conventional PLD technique is eliminated. This coaxial scanning PLD method is used to deposit a CIGS film, 500 nm thick, with thickness uniformity exceeding ±3% within a 5 cm diameter, and exhibiting a highly homogeneous elemental distribution.

Penetration performance of W/Cu double-layer shaped charge liners

Two kinds of W/Cu double-layer shaped charge liner（SCL） were prepared by chemical vapor deposition（CVD） combined with electroforming technique： A SCL with W inner layer and Cu outer layer, B SCL with Cu inner layer and W outer layer. The penetration properties of A and B SCLs were researched. The results show that the two SCLs can form continuous jet and the tip velocities of A and B jets are 7.4 and 6.3 km s^（-1）, respectively. The kinetic energy density（5.3 9 1011 J m-3） of A jet tip increases by 194.4 %compared with that（1.8 9 1011 J m-3） of B jet tip. B jet,however, exhibits deeper penetration depth at the same experimental conditions. The chemical component and microstructure of the area nearby the ballistic perforation were researched. Component analysis shows that both the jets are formed only from inner layer metal. Microstructure analysis shows that martensite and intermetallic form around ballistic perforation penetrated by A SCL due to the intensive interaction between W jet and steel target. The two kinds of newly formed ultrahard phases also hinder the jet from penetrating target further. As a result of relatively alleviative interaction between Cu jet and target, only solid solution rather than ultrahard phases forms around ballistic perforation penetrated by B SCL.

Boron-10 lined proportional counter development for thermal neutron detection

Purpose Neutrons detection is of paramount importance in nuclear physics experiments,reactor physics,monitoring and control of nuclear reactors and in radiation protection.Among the neutron detectors used are Proportional Counters(PC to BF3,boron deposition,3He),Our Detection and Measurements laboratory has embarked on a project to develop,design and build proportional counters with boron deposition mainly for gas filling,several prototypes of which have been produced.Method This work presents the Boron-10 Lined Proportional Counters(PC),developed and produced in the Detection and Measurements Department(DDM19).The PC was designed by adopting,for the electrodes,a stainless steel cathode 0.5 mm thick and a gold-plated tungsten anode with diameter of 25μm.The detectors are filled with an Ar-CH4 mixture(10%)at a pressure of 20 cmHg.The boron deposition is performed by the technique of electrophoresis.Result The results obtained using the DDM19 prototype PC(Detector produced in our Detection and Measurement laboratory,2019),show the advantage of electrophoresis as a better boron deposition technique,and the limitation of the surface mass of 10B to optimal values is around 0.5 at 0.6 mg/cm2.Conclusions The characteristics of the gas amplification in the mixture(Ar-CH4(CH410%)),were measured by different methods and compared with the values of the proportional reference counter LND232.The counting plates for the two reference meters LND232 and our DDM19 prototype from 200 to 300 V have slopes ranging from 6.5 to 10%/100 V,and gas amplification factors from 1436 to 1380,respectively.