{'fraction_non_alphanumeric': 0.019823788546255508, 'fraction_numerical': 0.012481644640234948, 'mean_word_length': 5.13963963963964, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
PROCESSING AND PROPERTIES OF SINTERED COPPER-IRON And COPPER-STEEL COMPOSITES

Copper matrix reinforced with iron or carbon steel particulate composites were made by means of the powder metallurgy route. The reinforcement particles were added to copper metal powders with the composition of 15 wt% Fe and mixed mechanically. Each mixture of the investigated powders was cold compacted at 624 MPa. The green compacts were sintered at 900 °C in dissociated ammonia atmosphere. Identification of the structure was performed on the basis of iron-copper phase diagram. Results of X-ray microprobe analysis allowed to find that the reinforcement particles were connected with copper matrix by solid solutions. Also the concentration of iron in copper across the iron (or steel)-copper matrix boundary was investigated. Measurements showed that the highest hardness of 41 HB could be achieved for Cu-steel composites because particles contained cementite. The same composites also had higher electrical conductivity (27 MS/m that was about 48 % of electrical conductivity of sintered copper) because their copper matrix contained lower concentration of iron atoms. Tribological tests showed that the wear mass loss of the copper-steel composites was approximately 2 times smaller than for the copper-iron composites and about 2.3 times smaller than for sintered copper.