Effect of sintering process on properties of CuSnZn alloy powder
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摘要: 提高金刚石工具的性能并控制其生产成本已成为工程应用领域的重点研究方向。本研究中,通过雾化法制备不同Zn质量分数(10.00%~30.00%)的CuSnZn合金粉末,在610~655 ℃不同的热压烧结温度和21 MPa的烧结压力下制备烧结节块,并对烧结节块的理论密度、洛氏硬度、抗弯强度、显微形貌进行分析。结果表明:随着Zn含量升高,CuSnZn合金粉末熔化温度逐渐降低,当Zn质量分数为30.00%时,熔化温度降低到848 ℃;当Zn质量分数为20.00%时,烧结节块致密度降低至97.6%;烧结节块的抗弯强度先升高后降低,当Zn质量分数为20.00%时,达到最大值542 MPa;烧结节块中的黄铜由α相逐渐转变为α + β相和α + β + β´相,其洛氏硬度显著提升;节块的断裂方式由沿晶断裂逐渐过渡到穿晶断裂。
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关键词:
- CuSnZn合金粉末 /
- 致密度 /
- 沿晶断裂
Abstract: Objectives: Diamond tools are crucial in stone processing, and their performance is directly related to processing quality and cost. With the rise of stone and labor costs, the performance requirements on diamond tools are also increasing, including sharpness, self sharpening, tool life, and cutting efficiency. To improve efficiency and reduce costs, users often increase the cutting machine power and speed, which further requires diamond tools to have higher sharpness and strength at the risk of breakage. A practical method method is to increase the content of tin (Sn) in the segment to enhance its brittleness without changing the diamond concentration and particle size. However, an increase in Sn content will reduce the strength of the segment and may lead to a decrease in the holding force between CuSn alloy and diamond. For example, the commonly used CuSn10 and CuSn15 pre alloy powders in industry have low strength and weak holding force on diamond. Therefore, it is necessary to improve the powder properties and processing technology. Methods: Adding Zn element to CuSn10 alloy powder can improve powder strength and holding force. CuSnZn-x alloy powder (mass fraction of Zn, x=10.00%, 15.00%, 20.00%, 25.00%, 30.00%) was prepared by atomization process. The hot pressing sintering temperatures were 610 ℃, 615 ℃, 630 ℃, 645 ℃, 655 ℃, and the sintering pressure was 21 MPa. The melting temperature of CuSnZn alloy powder was tested using a differential thermal analyzer. The density of the sintered segment was tested using Archimedes drainage method. The bending strength of the sintered segment was tested using mechanical performance testing equipment. The Rockwell hardness of the sintered segment was measured using a Rockwell hardness tester. The microstructure morphology of the sintered segment and its fracture were analyzed using scanning electron microscopy. Other performances of samples with different Zn contents were analyzed and compared as well, namely theoretical density, Rockwell hardness, and flexural strength, to study the influence of Zn content on sample microstructure. Results: With the increase of Zn content, the rate of decrease in melting temperature of CuSnZn alloy powder first increases and then decreases. When the Zn mass fraction is 30%, the melting temperature decreases to 848 ℃, which is 164 ℃ lower than that of CuSn10. As the Zn content increases, the brass in the sintered segment gradually transforms from the α phase to the α+β phase and then the α+β+β´ phase, resulting in a significant increase in the Rockwell hardness of the segment. The bending strength of the sintered segment first increases and then decreases, reaching a maximum value of 542 MPa when the Zn mass fraction is 20.00%. When the mass fraction of Zn is 10.00% and 15.00%, obvious toughness dimples are observed on the fracture surface of the sintered segment, and particle peeling is observed on the fracture surface. The peeling surface is smooth and flat, indicating grain boundary peeling fracture of the phase structure. When the mass fraction of Zn is 20.00% and 25.00%, a large number of cleavage fracture surfaces are observed on the fracture surface of the sintered segment, and a small amount of smooth concave transgranular fracture is observed, which is partially intergranular fracture and partially transgranular fracture. When the mass fraction of Zn is 30.00%, the fracture surface of the sintered segment is flat and smooth, and the crack passes through the phase interface and grain along the hard and brittle structure, which is transgranular fracture. Conclusions: Adding Zn element can effectively reduce the melting point of alloy powder, and with the increase of Zn content, the hardness of sintered samples increases while the toughness decreases. When the Zn content is 30.00%, the melting temperature of CuSnZn alloy powder reaches its minimum value. When the Zn content exceeds 25.00%, the strength of the sintered samples will gradually decrease. Therefore, in actual production, the appropriate amount of Zn addition and sintering process should be selected based on comprehensive consideration of demand.-
Key words:
- CuSnZn alloy powder /
- density /
- intergranular fracture
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表 1 CuSnZn合金粉末成分设计
Table 1. Composition design of CuSnZn alloy powder
牌号 元素质量分数 ω1 / % 理论密度 ρ / (g·cm−3) Cu Sn Zn CuSnZn-1 余量 10.00 10.00 8.55 CuSnZn-2 余量 10.00 15.00 8.44 CuSnZn-3 余量 10.00 20.00 8.34 CuSnZn-4 余量 10.00 25.00 8.24 CuSnZn-5 余量 10.00 30.00 8.15 表 2 烧结节块能谱分析及相组织分析
Table 2. Energy spectrum and phase structure analysis of sintered matrix
测量
序号元素质量分数 ω2 / % 存在的相 Cu Sn Zn 1 66.03 30.37 3.60 α + δ 2 78.67 7.07 14.26 α 3 63.07 26.02 10.91 α + δ 4 72.81 3.49 23.70 α 5 63.24 26.02 10.75 α + δ 6 74.41 4.64 20.95 α + β 7 55.69 20.69 23.62 α + δ + β + β´ 8 67.39 2.91 29.71 α + β + β´ 9 53.97 15.39 30.65 α + δ + β + β´ 10 65.10 1.17 33.74 α + β + β´ -
[1] 中国石材协会. 金刚石锯片在国内石材领域中的应用及市场前景 [J]. 石材,2012(12):25-28. doi: 10.3969/j.issn.1005-3352.2012.12.018China Stone Material Association. Application and market prospect of diamond saw blade in domestic stone material field [J]. Stone,2012(12):25-28. doi: 10.3969/j.issn.1005-3352.2012.12.018 [2] 李子石, 程凯. 金刚石锯片技术发展现状和走势分析 [J]. 石材,2014(6):27-30.LI Zishi, CHENG Kai. Diamond saw blade technology development status and trend analysis [J]. Stone,2014(6):27-30. [3] 甘树才, 杨春明, 徐吉静, 等. 油页岩灰渣制备人造大理石及其性能 [J]. 吉林大学学报,2011,41(3):879-884.GAN Shucai, YANG Chunming, XU Jijing, et al. Preparation of artificial marble from oil shale ash and its properties [J]. Journal of Jilin University,2011,41(3):879-884. [4] 栾芝芸, 孙建国. 新型金刚石节块圆片锯的切割性能试验 [J]. 工具技术,2000,34(7):7-8. doi: 10.3969/j.issn.1000-7008.2000.07.002LUAN Zhiyun, SUN Jianguo. Cutting performance test of a new diamond nodular block circular saw [J]. Tool Engineering,2000,34(7):7-8. doi: 10.3969/j.issn.1000-7008.2000.07.002 [5] 舒士韬. 关于提高大理石出材率和利用率的若干问题 [J]. 广东建材,1999(2):13-19.SHU Shitao. Some issues on improving marble yield and utilization rate [J]. Guangdong Building Materials,1999(2):13-19. [6] 王博, 冯振昌, 肖博. 影响金刚石锯片基体物理性能的关键因素分析 [J]. 施工技术,2016,45(12):796-797.WANG Bo, FENG Zhenchang, XIAO Bo. Key factors of the physical properties of the diamond Saw blades [J]. Construction Technology,2016,45(12):796-797. [7] 储志强, 郭学益, 刘东华. 切割石材用金刚石制品胎体粉末配方的设计依据和优化原则 [J]. 金属材料与冶金工程,2016(6):3-8.CHU Zhiqiang, GUO Xueyi, LIU Donghua. Design basis and optimization principles for the formulation of diamond product casing powder for cutting stone [J]. Metal Materials and Metallurgy Engineering,2016(6):3-8. [8] 于奇, 马佳, 钟素娟, 等. 铜锡预合金粉热压性能研究 [J]. 粉末冶金工业,2019,29(1):13-17.YU Qi, MA Jia, ZHONG Sujuan, et al. Study on hot pressing properties of Cu-Sn pre-alloyed powder [J]. Powder Metallurgy Industry,2019,29(1):13-17. [9] 蒙光海, 雷晓旭, 卢安军, 等. CuSn15和Fe对无压烧结金刚石工具胎体性能的影响 [J]. 粉末冶金技术,2015,33(2):105-110. doi: 10.3969/j.issn.1006-852X.2011.05.012MENG Guanghai, LEI Xiaoxu, LU Anjun, et al. Effects of CuSn15 and Fe on the properties of pressureless sintered diamond tools matrix [J]. Powder Metallurgy Technology,2015,33(2):105-110. doi: 10.3969/j.issn.1006-852X.2011.05.012 [10] 曹彩婷, 刘一波, 徐良, 等. 高Sn含量 Cu-Sn 预合金粉热压烧结行为及性能的研究 [J]. 金刚石与磨料磨具工程,2016,36(2):67-72.CAO Caiting, LIU Yibo, XU Liang, et al. Study of hot pressing sintering behavior and properties of high Sn content Cu-Sn pre-alloyed powders [J]. Diamond & Abrasives Engineering,2016,36(2):67-72. [11] 刘志环, 张绍和. FeNiCo 预合金粉末的烧结特性及其在金刚石绳锯中的应用 [J]. 中国有色金属学报,2019,29(6):1257-1267.LIU Zhihuan, ZHANG Shaohe. Sintering properties of FeNiCo pre-alloyed powder and its application in diamond wire saw [J]. The Chinese Journal of Nonferrous Metals,2019,29(6):1257-1267.