scholarly journals Technological increase of adhesive wear-resistance of parts added with chromium powder wire alloyed with complex of boron and nitrogen compounds

Author(s):  
Евгений Еремин ◽  
Evgeniy Yeryomin ◽  
Александр Лосев ◽  
Aleksandr Losev ◽  
Иван Пономарев ◽  
...  

It is shown that the structure of metal padded with powder wire having the following mixture: 15% Cr – 0,5% B4C – 0,5% BN – 2,5% TiB2 – 1,0% ZrB2, is a martensitic matrix with (Fe, Cr)2B boride eutectic, carbon boride of (Fe, Cr)7(C, B)3 type and ε –(Fe, Cr)2-3N nitrides. Such a wire can be used for strengthening weld deposition of parts operated under conditions of heavy friction loading.

1996 ◽  
Vol 457 ◽  
Author(s):  
Kang Jia ◽  
Traugott E. Fischer

ABSTRACTThe microstructure, mechanical properties, abrasion and wear resistance of WC-Co nanocomposites synthesized by the spray conversion technique by McCandlish, Kear and Kim have been investigated. The binder phase of WC-Co nanocomposites is enriched in W and C, compared to conventional cermets. Small amorphous regions exist in the binder despite the slow cooling after liquid phase sintering. Few dislocations are found in the WC grains. The increased WC content and the amorphous regions modify (i.e. strengthen) the binder phase of the composites. Vickers indentation measurements show a hardness of the nanocomposites reaching 2310 kg/mm2. While the toughness of conventional cermets decreases with increasing hardness, the toughness does not decrease further as the WC grain size decreases from 0.7 to 0.07 μm. but remains constant at 8 MPam1/2. Scratches caused by a diamond indenter are small, commensurate with their hardness. These scratches are ductile, devoid of the grain fracture that is observed with conventional materials. The abrasions resistance of nanocomposites is about double that of conventional materials, although their hardness is larger by 23% only. This is due to the lack of WC grain fragmentation and removal which takes place in conventional cermets. Sliding wear resistance of WC/Co is proportional to their hardness; no additional benefit of nanostructure is obtained. This results from the very small size of adhesive wear events in even large WC grains.


Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 738 ◽  
Author(s):  
Qiong Xu ◽  
Aibin Ma ◽  
Junjie Wang ◽  
Jiapeng Sun ◽  
Jinghua Jiang ◽  
...  

Relatively low compactness and unsatisfactory uniformity of reinforced particles severely restrict the performance and widespread industry applications of the powder metallurgy (PM) metal matrix composites (MMCs). Here, we developed a combined processing route of PM and equal channel angular pressing (ECAP) to enhance the mechanical properties and wear resistance of the SiCp/Al-Si composite. The results indicate that ECAP significantly refined the matrix grains, eliminated pores and promoted the uniformity of the reinforcement particles. After 8p-ECAP, the SiCp/Al-Si composite consisted of ultrafine Al matrix grains (600 nm) modified by uniformly-dispersed Si and SiCp particles, and the composite relative density approached 100%. The hardness and wear resistance of the 8p-ECAP SiCp/Al-Si composite were markedly improved compared to the PM composite. More ECAP passes continued a trend of improvement for the wear resistance and hardness. Moreover, while abrasion and delamination dominated the wear of PM composites, less severe adhesive wear and fatigue mechanisms played more important roles in the wear of PM-ECAP composites. This study demonstrates a new approach to designing wear-resistant Al-MMCs and is readily applicable to other Al-MMCs.


Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1456
Author(s):  
Qiang Wang ◽  
Runling Qian ◽  
Ju Yang ◽  
Wenjuan Niu ◽  
Liucheng Zhou ◽  
...  

In order to improve the wear resistance of 27SiMn steel substrate, Fe−based alloy coatings were prepared by laser cladding technology in the present study. In comparison to the conventional gravity powder feeding (GF) process, high−speed powder feeding (HF) process was used to prepare Fe−based alloy coating on 27SiMn steel substrate. The effect of diversified energy composition of powder materials on the microstructure and properties of coatings were systematically studied. X−ray diffractometer (XRD), optical microscope (OM) and scanning electron microscope (SEM) were used to analyze the phase structure and microstructure of Fe−based alloy coatings, and the hardness and tribological properties were measured by the microhardness tester and ball on disc wear tester, respectively. The results show that the microstructure of conventional gravity feeding (GF) coatings was composed of coarse columnar crystals. In comparison, owing to the diversification of energy composition, the microstructure of the high−speed powder feeding (HF) coatings consists of uniform and small grains. The total energy of the HF process was 75.5% of that of the GF process, proving that high−efficiency cladding can be achieved at lower laser energy. The refinement of the microstructure is beneficial to improve the hardness and wear resistance of the coating, and the hardness of the HF coating increased by 9.4% and the wear loss decreased to 80.5%, compared with the GF coating. The wear surface of the HF coating suffered less damage, and the wear mechanism was slightly adhesive wear. In contrast, wear was more serious in the GF coating, and the wear mechanism was transformed into severe adhesive wear.


2020 ◽  
Vol 993 ◽  
pp. 836-843
Author(s):  
Ke Guo ◽  
Zhi Qiang Zhang ◽  
Zhong Zheng Pei ◽  
Jie Xu ◽  
Yi Fan Feng

Here we developed a hot-pressed molded resin-based brake pad material reinforced by a nano sodium titanate whisker in comparison with nano potassium titanate whisker. The effect of the whiskers on the tribology behavior was investigated. Though nano sodium titanate whisker reinforced brake material showed higher porosity (+12.29% averagely) and lower hardness (-25.8% averagely) caused by the impurities, it exhibited improved ability in stabilizing the friction coefficient and enhancing 25.5%, 31.1%, 25.9% higher wear resistance, when the volume contents of whisker are 7.5%, 15% and 22.5%, respectively, compared to the nano potassium titanate whisker reinforced brake material. The wear mechanisms of the nano sodium titanate whisker reinforced brake materials were determined as embedded debris, delaminated crater, moderate layers transfer, uniform furrows, primary plateaus and secondary plateaus in similar size, indicating a main wear form of abrasive wear instead of adhesive wear.


Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2831 ◽  
Author(s):  
Alejandro Gonzalez-Pociño ◽  
Florentino Alvarez-Antolin ◽  
Juan Asensio-Lozano

Vanadis 10 steel is a powder metallurgy (PM) processed tool steel. It is a ledeburitic steel with 8% Cr and 10% V. By deliberately varying the process parameters related to the quenching, tempering, and nitriding of these steels, the aim of this study is to determine which of these parameters have a significant influence on its adhesive wear resistance. The research methodology employed was a Design of Experiments (DoE) with six factors and two levels for each factor. The tempering temperature, number of temperings, and carrying out of a thermochemical nitriding treatment were found to have a significant effect. To increase adhesive wear resistance, austenitization at 1100 °C with air cooling is recommended, followed by three temperings at 500 °C and a subsequent nitriding treatment. It should be noted that the quench cooling medium does not have a significant influence on wear resistance. Furthermore, (Fe,Cr)7C3 (M7C3 carbides) are transformed into carbonitrides during nitriding. However, (Fe,V)C (MC carbides) are not affected by this nitriding process.


Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 672 ◽  
Author(s):  
Bojan Podgornik ◽  
Mihael Brunčko ◽  
Peter Kirbiš

A novel high C high Si carbide free bainitic steel was developed for the production of cold work tools, knives, and rolls, requiring high hardness, toughness, as well as abrasive/adhesive wear resistance and resistance to galling at low costs. The steel was tribologically tested in dry sliding conditions under abrasive and adhesive wear mode, facilitated by using alumina and bearing steel ball as a counter-material, respectively. It was determined that carbide dissolution occurs under high contact pressures, thereby enriching the surrounding matrix with carbon and locally increasing the retained austenite content. The high retained austenite at the sliding interface increases the steels work hardening capacity and promotes superior wear resistance when compared to much more alloyed cold work tool steel, such as AISI D2. The steel has a high resistance to galling as determined by sliding against a soft steel bar due to its chemical composition.


Wear ◽  
1980 ◽  
Vol 61 (2) ◽  
pp. 219-231 ◽  
Author(s):  
A.J.T. Clemow ◽  
B.L. Daniell

2012 ◽  
Vol 619 ◽  
pp. 561-566 ◽  
Author(s):  
Lian Yong Zhang ◽  
Fang Hong Sun ◽  
Yan Hua Jiang

grind-hardening test was performed on 42CrMo steel in the paper. Microstructure of the hardened layer was observed and the wear-resistance of hardened specimens was done too. The results showed that microstructure of the fully hardened layer was mainly composed by lath martensite; microhardness of the hardened layer was above 700HV and the abrasive wear and the adhesive wear properties of hardened layer were 2~9 times than that of the base.


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