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Alloying treatment was performed on 38CrMoAl alloy steel by using continuous scanning electron beam to improve surface performance. The effects of the TiN/Ni ratio on the microstructure, phase composition and mechanical properties of the alloying layer were discussed. As the TiN fraction in the TiN/Ni mixed powder increased, fine equiaxed crystals develop at the top of the alloying layer. When the TiN fraction is 20%, the alloying layer is mainly composed of fine equiaxed crystals and columnar crystals that are uniformly distributed. The alloying layer with TiN mainly contains γ-Ni, Fe-Ni, as well as phases such as TiN, Cr23C6 and Cr7C3. The surface hardness can reach as high as 1140 HV when the TiN fraction is 20%, which is 3.7 times that of the alloying layer without TiN. Moreover, the friction coefficient and abrasion loss decreased by about 47% and 55%, respectively.

Single-pass and multi-pass electron beam surface modification (EBSM) are two of the most important scanning method in the field of electron beam processing. In this paper, microstructure evolution and surface properties of 40CrMn steel treated by multi-pass and single-pass EBSM are compared. It is found that there is obvious difference in microstructure evolution of the treated samples after two scanning modes of electron beam treatment due to these region experienced different thermal circles processes. Moreover, the slight difference in surface microhardness of specimens after single-pass and multi-pass electron beam treatment are supposed to be caused by the formation of tempered martensite and tempered sorbite in the overlap region after multi-pass electron beam treatment. And the wear resistance of the specimens were improved obviously under the two scanning modes of EBSM compared with the untreated specimens.

Continuous scanning electron beam process (CSEBP) was conducted on 40CrMn steel to enhance its mechanical properties. The influence of electron beam process parameters on the surface microstructures and mechanical properties of 40CrMn steel was investigated. The result shows that the cross-section of the sample after CSEBP contained three districts as follows: melted layer, heated affected zone and substrate. At a beam current of 5 mA, the surface microhardness increased from 309.7 HV to 692.8 HV, which was in 2.34 times of the substrate hardness. Additionally, the surface microhardness decreased nonlinearly with the increase of electron gun moving speed. At a moving speed of 120 mm/min, the surface microhardness reached a maximum value of 666.2 HV. At a moving speed of 300 mm/min, the surface roughness reduced from 1.754 μm to 0.801 μm. The wear loss of the samples after scanning electron beam treatment decreased significantly compared with the initial samples.

Scanning electron beam surface alloying can effectively improve the surface properties of metal samples. After tungsten alloying treatment on the surface of 45 steel by scanning electron beam, a strengthened layer consisting of alloying zone and heat-affected zone was formed on the surface. The microstructure in alloying zone is acicular martensite and columnar crystal, the microstructure in heat affected zone is acicular martensite and ferrite, and the matrix microstructure is ferrite and pearlite. With the increase of electron beam power, the columnar crystal content in alloying zone increases, the acicular martensite content in heat affected zone increases and the ferrite content decreases. The thickness of alloy zone and heat affected zone increases nonlinearly, and the surface hardness increases gradually. The maximum hardness of the sample surface is 1170HV, which is more than 5 times that of the matrix.

Ni60 cladding layers added with different amounts of rare-earth CeO2, Y2O3, and La2O3 were prepared on the surface of 6063 aluminum alloys through laser cladding. The effects of such cladding layers on the macroscopic morphology, section morphology, micro-hardness, phase composition, microstructure, and composition distribution of the laser clad Ni-based coating were investigated by performing metallographic microscopy, X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, and micro-hardness test. Cladding layers with the optimum rare-earth contents were 4% CeO2 + Ni60 cladding layer, 5% Y2O3 + Ni60 cladding layer, and 5% La2O3 +Ni60 cladding layer. The main phase composition of the cladding layers included β-NiAl (Cr), Al3Ni, AlNi3, and Al. The Ni60 cladding layers added with rare-earth oxides produced a chemical reaction that was involved in the cladding process to form stable rare-earth compounds. Ni60 cladding layers added with 4% CeO2, 5% Y2O3, and 5% La2O3 were preferable over those without rare-earth oxides, as the former displayed smoother micro-morphologies without obvious pores and cracks. The dendritic structures of the Ni60 cladding layers were coarse; moreover, many grain segregations that were accompanied by a large number of pores were observed in the local area. By contrast, the Ni60 cladding layers added with rare-earth oxides displayed compact dendritic structures, and the grains were obviously refined. The hardness of the cladding layers from the surface to the substrate was gradually decreased as the cladding layer depth increased. Compared with Ni60 cladding layer, the transitions of Ni, Al, Cr, and other elements in the Ni60 cladding layers added with different amounts of CeO2, Y2O3, and La2O3 were became more observable with increasing depth, and the dilution rate of the cladding layer was reduced.

Surface modification is an important component of improving mechanical properties in mold manufacturing. In this work we present a method for surface modification on 5CrMnMo mold steel with continuous scanning electron beam. The surface morphology and microstructure of the processed samples have been investigated by the three-dimensional measuring laser microscope and scanning electron microscope respectively. The changes in the surface roughness, microhardness and wear resistance before and after electron beam treatment were also examined. The variation regularity of surface roughness and microhardness under the changes of beam current was found. Comparing with the initial samples, at a beam current of 7 mA, the roughness decreased from 2.23 μm to 0.90 μm, while the hardness increased from 355 HV to 656 HV. The wear resistance of modified layer was improved remarkably compared with the initial state. Additionally, the composite microstructure of acicular and lath martensites were obtained by the martensitic transformation occurring in the modified layer. The samples which were irradiated by electron beam contained three areas as follows: melted layer, heated affected zone and substrate matrix.

The surface WC/Ni-Co based alloying treatment of 30CrMnSi steel was carried out using scanning electron beam technology, and the tissue distribution after alloying were tested and investigated. The results show that the cross-section of the alloyed specimen consists of three parts: the alloy layer, the heat affected zone and the substrate. The thickness of the alloy layer was increased by 18.3 μm compared to the thickness of the pre-coated layer. The alloy layer is organised in a composite gradient, consisting of martensite and ledeburite with carbides.

Surface alloying by scanning electron beams can improve the microstructure and mechanical properties of steel. In this study. Four electron energy densities were selected during the alloying process: E1 = 1.5J/cm2, E2 = 2.9J/cm2, E3 = 4.5J/cm2 and E4 = 5.9J/cm2. The obtained results show that the sample surface is composed of alloying zone and heat-affected zone. The microstructure of the alloy zone is concealed acicular martensite and molybdenum carbide particles. The microhardness of this area is 1250HV. The sample treated with an energy density of 5.9J/cm2 has the least amount of wear. After alloying treatment, the microhardness and wear amount of the scanned samples are significantly improved.

The electron beam technology was used to polish and strengthen the surface of 45 steel. It was established that the mechanical scratches on the surface of 45 steel disappeared completely, and the roughness was reduced to 0.412 ± 0.02 μm. The samples which were irradiated by electron beam contained three areas as follows: fusion zone, heated affected zone and based metal. The fusion zone was mainly composed of acicular martensite, the heated affected zone was composed of martensite and ferrite. The hardness of the 45 steel sub-surface layer was slightly higher than surface layer. The hardness can be increased from 290 HV to 912 HV.

It is difficult to achieve 3Cr2Mo plastic mold steel with good comprehensive mechanical properties by traditional surface modification methods. In this study, electron beam (EB) polishing technology was used to improve the surface quality of 3Cr2Mo plastic mold steel. Surface morphology, microhardness, wear resistance, and variation regularity in width and depth of the modified layer were also investigated. The surface morphology of 3Cr2Mo was found to be a composite microstructure of acicular and lath martensites. The surface roughness was improved by this technique. Additionally, in the depth and width of the modified layer, the microhardness and wear resistance showed a positive effect as the beam current increased. These results indicated that EB irradiation could be an efficient method for mold surface polishing.

The surface alloying of scanning electron beam can improve the microstructure and mechanical properties of steel materials. In this paper, Cr/Ni alloying treatment was performed on 35CrMo alloy structure steel by using continuous scanning electron beam to improve surface performance. The influence of scanning electron beam technology on the structure of alloy layer is studied, and the influence of coating thickness on the structure and properties of the alloying layer is discussed. The results show that the surface of 35CrMo steel is composed of alloying layer, heat affected zone and matrix. The microstructure of the alloying layer is short columnar crystal, equiaxed crystal and acicular martensite. The surface hardness can reach 770HVwhen the coating thickness is 5μm, which is 2 times of the matrix. With the increase of Cr/Ni coating thickness, the surface of sample hardness decreases, and the corrosion resistance of the sample increases.

Objective Construction of monoclonal antibody cell lines against human free prostate specific antigen (f-PSA), and establish double antibody sandwich CLIA for human f-PSA. Methods Two hybridoma cell lines secreting anti-f-PSA mAb were obtained by hybridoma technique. The cell lines were expanded by spinner bottles and purified by affinity purification, from which the antibodies were tested for antibody titers, specificity, epitopes by ELISA and affinity by surface plasmon resonance. Establishment, analysis and performance evaluation of a double mAbs sandwich CLIA system using standard curve quantitative method. In total 426 (130 gray area) clinical specimens were used for system comparison between our assay and Roche f-PSA assay. Results anti- f-PSA(f-10-1, f-14-1) mAbs were obtained. The CLIA system with detection range of 0.1-30 ng/mL, sensitivity of 0.05 ng/mL, relative detection deviation of ±5% and not cross-react with the tumor marker AFP, CEA and c-PSA. The correlation coefficient of our reagent with Roche's was 0.99. The positive coincidence rate, negative coincidence rate and total coincidence rate of gray area specimens were all higher than 90%. Conclusion mAbs against human f-PSA were successfully prepared, and the double mAbs sandwich CLIA for specific quantitative detection of human f-PSA was established.

To prepare the anti-human carbohydrate antigen 50(CA50) monoclonal antibody (mAb), characterize its immunological features and establish a chemiluminescence immunoassay system with it.BALB/c mice were immunized with human CA50 antigen for preparing mAb using hybridoma technique. Stable anti-CA50-secreting hybridoma cell lines were obtained after screening. The mAbs were purified using protein A after expanding culture. The chemiluminescence immunoassay system was established and evaluated in its linear range, accuracy, sensitivity, reproducibility, and the blood samples were tested with it.Four hybridoma cell lines were obtained respectively and their titers were above 1:10(8). Anti-CA50 mAbs nearly had no cross-reaction with CA125, CA153, CA199 and CA724. The linear detection of the chemiluminescence immunoassay system covered a range 0-500 U/mL. The recovery rate for accuracy was 107.08% and its sensitivity was 0.83 U/mL. The assay was highly repeatable [coefficient of variation (CV)10%]. The correlation coefficient with the test of reference reagent was 0.96.The monoclonal antibodies against human CA50 had been screened and a chemiluminescence immunoassay system for human CA50 detection had been established successfully.

To prepare the monoclonal antibodies (mAbs) against human carbohydrate antigen 19-9 (CA19-9) and establish a double-antibody sandwich chemiluminescent immunoassay (CLIA) detection system for CA19-9 in the human serum.BALB/c mice were immunized with human CA19-9 antigen. The mAbs were obtained by hybridoma technique. The purity, titer, specificity and pairing of the mAbs were characterized and the sandwich CLIA system was established. The system was evaluated in its accuracy, limit of detection, linearity and repetitiveness after optimization of coating buffer, coating concentration and pipetting mode, and the serum sample was tested with it.Four mAbs named #1-1, #2-1, #3-1 and #4-1 were obtained against human CA19-9. The titers of the anti-CA19-9 mAbs were above 10(-8). The mAbs had nearly no cross-reaction with CA125, CA15-3 and CA72-4. The double-antibody sandwich CLIA system was established by #3-1 mAb and #2-1 mAb-HRP. After optimization, its property was detection range of 0-1 000 U/mL, limit detection of 2.0 U/mL, linear correlation coefficient of 0.9999. The results which were contrasted with Roche test showed that: Kappa0.75, r(correlation coefficient)0.9.The mAbs against human CA9-9 have been prepared and a sandwich CLIA system for detecting CA19-9 in the human serum has been established successfully.

To prepare the monoclonal antibodies (mAbs) against human carbohydrate antigen 15-3 (CA15-3) and establish a double-antibody sandwich chemiluminescent immunoassay (CLIA) system for detecting CA15-3 in the human serum.BALB/c mice were immunized with human CA15-3 antigen. Spleen cells of the immunized mice were fused with Sp2/0 cells and the positive hybridoma cells were selected and subcloned. The supernatant was taken for purify mAbs using protein A chromatography. The purity, titer, epitope and subtype of the mAbs were characterized and the sandwich CLIA system was established. The system was evaluated in its accuracy, limit of detection, linearity, repetitiveness and specificity.Five hybridoma cell lines named #3-1-3, #5-2-2, #11-2-2, #12-1-3 and #16-1-3 were obtained respectively, which are of strong positive signal and high secretion. The titers of the mAbs secreted by these hydridomas were above 10(-8); g/mL. All of the mAbs expressed κ light chains, and their heavy chains were as follows: #3-1-3 mAb had IgG2a, #5-2-2 mAb and #12-1-3 mAb had IgG2b, #11-2-2 mAb and #16-1-3 mAb had IgG3. The double-antibody sandwich CLIA system had a good linear relationship between 0.59 U/mL and 300 U/mL. The recovery rate for accuracy was 97.45% and the limit of detection was 0.59 U/mL. The assay was highly linear (correlation coefficient 0.9978) and highly repeatable [coefficient of variation (CV)10%]. This CLIA system was also highly specific without cross-reactivity to the tumor marker AFP, CEA, CA50, CA19-9 and CA72-4.The mAbs against human CA15-3 have been prepared and a sandwich CLIA system for detecting CA15-3 in the human serum has been established successfully, which provides a basis for CA15-3 quantification and clinical application.

Formation of Fe–Al composite thick layers using electron beam surface alloying process with nanometer iron powders have been investigated to improve the surface hardness and the wear resistance of 6061 aluminum alloy substrate. In this paper, the processes of electron beam surface modification on 6061 aluminum surface which added nanometer iron powder by electron beam surface alloying technique were studied. The microstructures and phase structures of alloying layers were analyzed by optical microscope, SEM and EDS, respectively. The surface hardness of alloying layers was measured. Friction wear test of the alloying layers were also carried out. The results indicate that hypo-eutectic microstructure was formed with fine grains, a number of new phases of intermetallic compounds were yielded and network structures were formed after electron beam surface alloying of 6061 aluminum alloy. The surface hardness and wear resistance of 6061 aluminum alloy was obviously improved after electron beam modification. It is better than direct electron beam surface treatment.

The surface hardness and wear resistance of aluminum alloy are both improved by means of scanning electron beam. In this paper, the strengthen treatment of the ADC12 aluminum surface, which is added nano-sized Al2O3-Al powder, was carried out by scanning electron beam. The microstructures and phase structures of ceramic layers were analyzed by using optical microscope, scanning electron microscope(SEM) and energy disperse spectroscopy(EDS), respectively. The surface hardness and friction wear of ceramic layers were measured. The research results show that the 2mm ceramic layer, the complex compounds and the new phases were generated. At the same time, the re-melting microstructures were also formed on the interface between ceramic layer and the base material. The surface hardness is as 1.56 times as the substrate. The wear resistance was obviously improved through electron beam modification.